Difference between revisions of "TCP/IP: Quagga BGP"
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Two major BGP strong points are: | Two major BGP strong points are: | ||
− | + | ||
− | + | * se of TCP. BGP communicates with the other BGP routers (called peers) through TCP which is the most reliable protocol. | |
− | + | * The notion of Autonomous System (AS). It is a group of IP networks under common administration and common routing policies. It is composed of a variable number of BGP routers. | |
− | + | ||
− | |||
− | The notion of Autonomous System (AS). It is a group of IP networks under common administration and common routing policies. | ||
− | It is composed of a variable number of BGP routers. | ||
We will give in the tables below some key points to compare BGP with two other well known routing protocols, OSPF and RIP, as well as some explanations about the BGP best path selection. | We will give in the tables below some key points to compare BGP with two other well known routing protocols, OSPF and RIP, as well as some explanations about the BGP best path selection. | ||
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Check that the zebra, ospfd and bgpd daemons are activated on Quagga A: | Check that the zebra, ospfd and bgpd daemons are activated on Quagga A: | ||
− | #vim /etc/quagga/daemons | + | #vim /etc/quagga/daemons |
− | zebra=yes | + | zebra=yes |
− | bgpd=yes | + | bgpd=yes |
− | ospfd=yes | + | ospfd=yes |
− | ospf6d=no | + | ospf6d=no |
− | ripd=no | + | ripd=no |
− | ripngd=no | + | ripngd=no |
− | isisd=no | + | isisd=no |
Check that the zebra and bgpd daemons are activated on Quagga B: | Check that the zebra and bgpd daemons are activated on Quagga B: | ||
− | #vim /etc/quagga/daemons | + | #vim /etc/quagga/daemons |
− | zebra=yes | + | zebra=yes |
− | bgpd=yes | + | bgpd=yes |
− | ospfd=no | + | ospfd=no |
− | ospf6d=no | + | ospf6d=no |
− | ripd=no | + | ripd=no |
− | ripngd=no | + | ripngd=no |
− | isisd=no | + | isisd=no |
If you changed your daemons files, restart the quagga service: | If you changed your daemons files, restart the quagga service: | ||
− | #vim /etc/init.d/quagga restart | + | #vim /etc/init.d/quagga restart |
+ | |||
Set the Quagga A hostname in the /etc/quagga/vtysh.conf file: | Set the Quagga A hostname in the /etc/quagga/vtysh.conf file: | ||
− | #vim /etc/quagga/vtysh.conf | + | #vim /etc/quagga/vtysh.conf |
− | ! | + | |
− | ! Sample | + | ! |
− | ! | + | ! Sample |
− | ! service integrated-vtysh-config | + | ! |
− | hostname Quagga_A | + | ! service integrated-vtysh-config |
− | username root nopassword | + | hostname Quagga_A |
− | ! | + | username root nopassword |
+ | ! | ||
Set the Quagga B hostname in the /etc/quagga/vtysh.conf file: | Set the Quagga B hostname in the /etc/quagga/vtysh.conf file: | ||
− | #vim /etc/quagga/vtysh.conf | + | #vim /etc/quagga/vtysh.conf |
− | ! | + | |
− | ! Sample | + | ! |
− | ! | + | ! Sample |
− | ! service integrated-vtysh-config | + | ! |
− | hostname Quagga_B | + | ! service integrated-vtysh-config |
− | username root nopassword | + | hostname Quagga_B |
− | ! | + | username root nopassword |
+ | ! | ||
Don't forget to activate the ip forwarding on the Quagga A and Quagga B routers! | Don't forget to activate the ip forwarding on the Quagga A and Quagga B routers! | ||
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− | interface FastEthernet0/1 | + | interface FastEthernet0/1 |
− | + | ip address 10.0.2.99 255.255.255.0 | |
− | + | no shutdown | |
− | interface FastEthernet0/0 | + | interface FastEthernet0/0 |
− | + | ip address 10.0.1.99 255.255.255.0 | |
− | + | no shutdown | |
− | interface Loopback 1 | + | interface Loopback 1 |
− | + | ip address 50.0.1.99 255.255.255.255 | |
− | Cisco_2651_A | + | Cisco_2651_A |
− | router ospf 1 | + | router ospf 1 |
− | + | network 10.0.1.0 0.0.0.255 area 0 | |
− | + | network 10.0.2.0 0.0.0.255 area 0 | |
− | + | network 50.0.1.99 0.0.0.0 area 0 | |
− | line vty 0 4 | + | line vty 0 4 |
− | + | no login | |
− | enable secret password | + | enable secret password |
SWITCH L3 3750 IOS: 12.2-25.SEE2 | SWITCH L3 3750 IOS: 12.2-25.SEE2 | ||
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See the entire configuration | See the entire configuration | ||
− | interface vlan 1 | + | interface vlan 1 |
− | + | ip address 10.0.1.1 255.255.255.0 | |
− | + | no shutdown | |
− | interface FastEthernet1/0/1 | + | interface FastEthernet1/0/1 |
− | + | switchport access vlan 1 interface eth0 | |
− | + | ip address 10.0.2.2/24 | |
− | + | link-detect | |
+ | interface vlan 2 | ||
+ | ip address 100.0.1.1 255.255.255.0 | ||
+ | no shutdown | ||
+ | interface FastEthernet1/0/2 | ||
+ | switchport access vlan 2 interface eth1 | ||
+ | ip address 100.0.2.2/24 | ||
+ | link-detect | ||
− | interface | + | interface Loopback 1 |
− | + | ip address 50.0.1.1 255.255.255.255 | |
− | + | interface lo | |
− | + | ip address 50.0.1.2/32 | |
− | + | link-detect | |
− | + | hostname Cisco_3750_L3 | |
− | + | router ospf 1 | |
+ | redistribute connected metric 1000 | ||
+ | metric-type 1 subnets | ||
+ | redistribute bgp 65001 metric 1000 | ||
+ | metric-type 1 subnets | ||
+ | network 10.0.1.0 0.0.0.255 area 0 router ospf | ||
+ | redistribute connected metric 2000 | ||
+ | |||
+ | redistribute bgp metric 2000 | ||
+ | network 10.0.2.0/24 area 0.0.0.0 | ||
− | + | router bgp 65001 | |
− | + | no synchronization | |
− | + | bgp router-id 50.0.1.1 | |
− | + | network 50.0.1.1 mask 255.255.255.255 | |
− | + | redistribute connected | |
− | + | redistribute ospf 1 | |
− | + | neighbor 10.0.2.2 remote-as 65001 | |
− | + | neighbor 100.0.1.3 remote-as 65003 | |
− | + | neighbor 100.0.1.3 route-map r2 in | |
− | + | no auto-summary | |
− | + | bgp config-type cisco | |
− | + | router bgp 65001 | |
− | + | no synchronization | |
+ | bgp router-id 50.0.1.2 | ||
+ | network 50.0.1.2 mask 255.255.255.255 | ||
+ | redistribute connected | ||
+ | redistribute ospf | ||
+ | neighbor 10.0.1.1 remote-as 65001 | ||
+ | neighbor 100.0.2.4 remote-as 65004 | ||
+ | neighbor 100.0.2.4 route-map r2 in | ||
+ | no auto-summary | ||
+ | route-map r2 permit 10 | ||
+ | set local-preference 333 route-map r2 permit 10 | ||
+ | set local-preference 222 | ||
+ | line vty 0 4 | ||
+ | no login | ||
+ | line vty | ||
+ | no login | ||
+ | enable secret password | ||
+ | enable password password | ||
− | + | ip routing | |
− | + | ip multicast-routing distributed | |
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− | ip routing | ||
− | ip multicast-routing distributed | ||
ROUTER 2651 B IOS: 12.2-23a | ROUTER 2651 B IOS: 12.2-23a | ||
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See the entire configuration | See the entire configuration | ||
− | interface FastEthernet0/0 | + | interface FastEthernet0/0 |
− | + | ip address 100.0.1.3 255.255.255.0 | |
− | + | no shutdown interface eth0 | |
− | + | ip address 200.0.1.5/24 | |
− | + | link-detect | |
− | interface FastEthernet0/1 | + | interface FastEthernet0/1 |
− | + | ip address 200.0.1.3 255.255.255.0 | |
− | + | no shutdown interface eth1 | |
− | + | ip address 200.0.2.5/24 | |
− | + | link-detect | |
− | interface Loopback 1 | + | interface Loopback 1 |
− | + | ip address 50.0.1.3 255.255.255.255 | |
− | + | interface lo | |
− | + | ip address 50.0.1.5/32 | |
− | + | link-detect | |
− | hostname Cisco_2651_B | + | hostname Cisco_2651_B |
− | router bgp 65003 | + | router bgp 65003 |
− | + | bgp router-id 50.0.1.3 | |
− | + | network 50.0.1.3 mask 255.255.255.255 | |
− | + | redistribute connected | |
− | + | neighbor 100.0.1.1 remote-as 65001 | |
− | + | neighbor 200.0.1.5 remote-as 65005 | |
− | + | neighbor 200.0.1.5 route-map r3 out | |
− | + | no auto-summary router bgp 65005 | |
− | + | bgp router-id 50.0.1.5 | |
− | + | network 50.0.1.5 mask 255.255.255.255 | |
− | + | redistribute connected | |
− | + | neighbor 200.0.1.3 remote-as 65003 | |
− | + | neighbor 200.0.2.4 remote-as 65004 | |
− | + | no auto-summary | |
− | route-map r3 permit 10 | + | route-map r3 permit 10 |
− | + | set metric 55 | |
− | line vty 0 4 | + | line vty 0 4 |
− | + | no login | |
− | + | line vty | |
− | + | no login | |
− | enable secret password enable password password | + | enable secret password enable password password |
ROUTER 2651 C IOS: 12.2-23a | ROUTER 2651 C IOS: 12.2-23a | ||
See the entire configuration | See the entire configuration | ||
− | |||
− | + | interface FastEthernet0/0 | |
− | interface FastEthernet0/0 | + | ip address 100.0.2.4 255.255.255.0 |
− | + | no shutdown | |
− | + | interface FastEthernet0/1 | |
− | interface FastEthernet0/1 | + | ip address 200.0.2.4 255.255.255.0 |
− | + | no shutdown | |
− | + | interface Loopback 1 | |
− | interface Loopback 1 | + | ip address 50.0.1.4 255.255.255.255 |
− | + | router bgp 65004 | |
− | router bgp 65004 | + | bgp router-id 50.0.1.4 |
− | + | network 50.0.1.4 mask 255.255.255.255 | |
− | + | redistribute connected | |
− | + | neighbor 100.0.2.2 remote-as 65001 | |
− | + | neighbor 200.0.2.5 remote-as 65005 | |
− | + | neighbor 200.0.2.5 route-map r99 out | |
− | + | no auto-summary | |
− | + | hostname Cisco_2651_C | |
− | hostname Cisco_2651_C | + | route-map r99 permit 10 |
− | route-map r99 permit 10 | + | set metric 99 |
− | + | line vty 0 4 | |
− | line vty 0 4 | + | no login |
− | |||
− | enable secret password | + | enable secret password |
+ | |||
Top of the page | Top of the page | ||
Line 402: | Line 399: | ||
CISCO 2651 A | CISCO 2651 A | ||
− | Cisco_2651_A#show ip int brief | + | Cisco_2651_A#show ip int brief |
+ | |||
+ | Interface IP-Address OK? Method Status Protocol | ||
+ | FastEthernet0/0 10.0.1.99 YES NVRAM up up | ||
+ | FastEthernet0/1 10.0.2.99 YES NVRAM up up | ||
+ | Loopback1 50.0.1.99 YES NVRAM up up | ||
− | + | Cisco_2651_A#show ip route | |
− | |||
− | |||
− | |||
− | Cisco_2651_A#show ip route | ||
− | Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP | + | Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP |
− | + | D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area | |
− | + | N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 | |
− | + | E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP | |
− | + | i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 | |
− | + | ia - IS-IS inter area, * - candidate default, U - per-user static route | |
− | + | o - ODR, P - periodic downloaded static route | |
− | + | ||
Gateway of last resort is not set | Gateway of last resort is not set | ||
− | + | 50.0.0.0/32 is subnetted, 6 subnets | |
− | O E1 50.0.1.3 [110/1001] via 10.0.1.1, 00:37:09, FastEthernet0/0 | + | O E1 50.0.1.3 [110/1001] via 10.0.1.1, 00:37:09, FastEthernet0/0 |
− | O E2 50.0.1.2 [110/2000] via 10.0.2.2, 00:37:15, FastEthernet0/1 | + | O E2 50.0.1.2 [110/2000] via 10.0.2.2, 00:37:15, FastEthernet0/1 |
− | O E1 50.0.1.1 [110/1001] via 10.0.1.1, 00:37:15, FastEthernet0/0 | + | O E1 50.0.1.1 [110/1001] via 10.0.1.1, 00:37:15, FastEthernet0/0 |
− | O E1 50.0.1.5 [110/1001] via 10.0.1.1, 00:36:22, FastEthernet0/0 | + | O E1 50.0.1.5 [110/1001] via 10.0.1.1, 00:36:22, FastEthernet0/0 |
− | O E1 50.0.1.4 [110/1001] via 10.0.1.1, 00:35:56, FastEthernet0/0 | + | O E1 50.0.1.4 [110/1001] via 10.0.1.1, 00:35:56, FastEthernet0/0 |
− | C 50.0.1.99 is directly connected, Loopback1 | + | C 50.0.1.99 is directly connected, Loopback1 |
− | + | 100.0.0.0/24 is subnetted, 2 subnets | |
− | O E1 100.0.1.0 [110/1001] via 10.0.1.1, 00:37:15, FastEthernet0/0 | + | O E1 100.0.1.0 [110/1001] via 10.0.1.1, 00:37:15, FastEthernet0/0 |
− | O E2 100.0.2.0 [110/2000] via 10.0.2.2, 00:12:48, FastEthernet0/1 | + | O E2 100.0.2.0 [110/2000] via 10.0.2.2, 00:12:48, FastEthernet0/1 |
− | O E1 200.0.1.0/24 [110/1001] via 10.0.1.1, 00:37:09, FastEthernet0/0 | + | O E1 200.0.1.0/24 [110/1001] via 10.0.1.1, 00:37:09, FastEthernet0/0 |
− | O E1 200.0.2.0/24 [110/1001] via 10.0.1.1, 00:36:22, FastEthernet0/0 | + | O E1 200.0.2.0/24 [110/1001] via 10.0.1.1, 00:36:22, FastEthernet0/0 |
− | + | 10.0.0.0/24 is subnetted, 2 subnets | |
− | C 10.0.2.0 is directly connected, FastEthernet0/1 | + | C 10.0.2.0 is directly connected, FastEthernet0/1 |
− | C 10.0.1.0 is directly connected, FastEthernet0/0 | + | C 10.0.1.0 is directly connected, FastEthernet0/0 |
− | Cisco_2651_A#show ip ospf database | + | |
+ | Cisco_2651_A#show ip ospf database | ||
+ | |||
+ | OSPF Router with ID (50.0.1.99) (Process ID 1) | ||
+ | |||
+ | Router Link States (Area 0) | ||
+ | |||
+ | Link ID ADV Router Age Seq# Checksum Link count | ||
+ | 50.0.1.1 50.0.1.1 357 0x80000004 0x003417 1 | ||
+ | 50.0.1.2 50.0.1.2 555 0x80000004 0x00CC90 1 | ||
+ | 50.0.1.99 50.0.1.99 404 0x80000005 0x00236B 3 | ||
+ | |||
+ | Net Link States (Area 0) | ||
+ | |||
+ | Link ID ADV Router Age Seq# Checksum | ||
+ | 10.0.1.99 50.0.1.99 404 0x80000002 0x009CCC | ||
+ | 10.0.2.99 50.0.1.99 404 0x80000002 0x009FC7 | ||
+ | |||
+ | Type-5 AS External Link States | ||
+ | |||
+ | Link ID ADV Router Age Seq# Checksum Tag | ||
+ | 50.0.1.1 50.0.1.1 357 0x80000002 0x005B84 0 | ||
+ | 50.0.1.2 50.0.1.2 502 0x80000003 0x00C3CA 0 | ||
+ | 50.0.1.3 50.0.1.1 357 0x80000002 0x00BB38 65003 | ||
+ | 50.0.1.4 50.0.1.1 357 0x80000002 0x00B141 65003 | ||
+ | 50.0.1.5 50.0.1.1 357 0x80000002 0x00A74A 65003 | ||
+ | 100.0.1.0 50.0.1.1 357 0x80000002 0x00D8D5 0 | ||
+ | 100.0.2.0 50.0.1.2 834 0x80000001 0x00441B 0 | ||
+ | 200.0.1.0 50.0.1.1 357 0x80000002 0x00342C 65003 | ||
+ | 200.0.2.0 50.0.1.1 357 0x80000002 0x002936 65003 | ||
+ | |||
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CISCO 3750 L3 | CISCO 3750 L3 | ||
− | Cisco_3750_L3#show ip int brief | + | Cisco_3750_L3#show ip int brief |
+ | |||
+ | Interface IP-Address OK? Method Status Protocol | ||
+ | Vlan1 10.0.1.1 YES NVRAM up up | ||
+ | Vlan2 100.0.1.1 YES NVRAM up up | ||
+ | FastEthernet1/0/1 unassigned YES NVRAM up up | ||
+ | FastEthernet1/0/2 unassigned YES NVRAM up up | ||
+ | ... ... ... ... ... ... | ||
+ | Loopback1 50.0.1.1 YES NVRAM up up | ||
− | + | Cisco_3750_L3#show ip route | |
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | Cisco_3750_L3#show ip route | ||
− | Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP | + | Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP |
− | + | D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area | |
− | + | N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 | |
− | + | E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP | |
− | + | i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 | |
− | + | ia - IS-IS inter area, * - candidate default, U - per-user static route | |
− | + | o - ODR, P - periodic downloaded static route | |
Gateway of last resort is not set | Gateway of last resort is not set |
Latest revision as of 11:00, 25 December 2018
1. CASE PRINCIPLE
Some words about BGP.
This tutorial is dedicated to the BGP (Border Gateway Protocol) dynamic routing protocol, for which the fourth and last version of BGP has been released in 1994.
BGP is mainly used by Service providers to perform the routing inside the Internet or to provide connectivity between the remote sites of a company with technologies like MPLS.
BGP is not scalable for a small to medium environment (up to 100 routers) because of its slow convergence time compared to the RIP or OSFP routing protocol. At the same time it can be very complex to configure and needs powerful (and very expensive) hardware to be run comfortably. This is why BGP should normally only be used by service providers or companies with a very large number of routers.
To give an example, in July 2007 more than 200'000 BGP entries were found on an internet router and are growing each day. Because of this high number of routes, the variation of the routing table will require a lot of resources and, as a consequence, the hardware must be very powerful. Cisco Systems (with its 12000 series routers) and Juniper share this lucrative market. For private networks, it is also possible to use BGP on "smaller" routers like the Cisco 7200 or 3800 series routers. Of course, Quagga supported by a good appliance can be comfortable in these environments too.
Two major BGP strong points are:
- se of TCP. BGP communicates with the other BGP routers (called peers) through TCP which is the most reliable protocol.
- The notion of Autonomous System (AS). It is a group of IP networks under common administration and common routing policies. It is composed of a variable number of BGP routers.
We will give in the tables below some key points to compare BGP with two other well known routing protocols, OSPF and RIP, as well as some explanations about the BGP best path selection.
Browse the web or buy a good book to find more details about this complex routing protocol.
Routing protocols comparison:
RIP OSPF BGP
Version: v2 v2 v4 RFC: 2453 2328 1771 Date: 1998 1998 1994
IGP - EGP: (1) IGP IGP EGP Type: Distance vector Link state Path vector Algorithm: Bellman-Ford Dijkstra Best Path Selection
Convergence: (2) Medium Fast Slow Administrative distance: 120 110 20 OSI level / port: UDP / 520 IP / 89 TCP / 179
Configuration complexity: Easy Medium Hard to very hard Routing granularity: Router Router Autonomous System (3) Scalable for: < 100 routers < 100 routers > 100 routers Resource consumption: Low Low to Medium High (1)
(2)
(3)
IGP stands for Interior Gateway Protocols, EGP for Exterior Gateway Protocols.
EGPs are used between independent administrative entities, often called autonomous systems and IGPs are used inside them. Convergence time: time needed for the routers to update their routing table after a change in the network topology. When several paths are available for a specific network, BGP choose the route crossing the smallest number of autonomous systems. BGP path selection process:
The BGP path selection process is used if there are several routes available for a network. You can see it with the "show ip bgp" command. This command must not be confounded with the "show ip route" command where only the best routes are displayed on the screen.
To get full details, you can read the Cisco webpage about the BGP path selection process. Click on an attribute name to get an example.
ATTRIBUTE NAME PREFERENCE VALUE TRANSMISSION DESCRIPTION
1. Weight (a) Highest Local to router Cisco & Quagga specific 2. Local Preference Highest Global within AS How to exit the AS if multiple paths 3. Path Shortest 4. Origin Code Lowest IGP or "i" < EGP or "e" < Incomplete or "?" (b) 5. MED (Metric) Lowest Transmitted to the neighbors AS only (a) (b) By default, a directly connected route takes a weight of 32768. An origin code of incomplete is due to route redistribution into BGP. Case study principle
Here are the functionalities we will test in our BGP scenario:
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EBGP (external BGP): BGP between the autonomous systems.
EBGP is running between Cisco 3750 L3 and Cisco 2651 A, Cisco 2651 A and Quagga B, Quagga B and Cisco 2651 C, Cisco 2651 and Quagga A.
IBGP (Internal BGP): BGP inside an AS. IBGP is running between Cisco 3750 L3 and Quagga A.
BGP to OSPF redistribution: On Cisco 3750 L3: BGP routes are injected into OSPF with a metric of 1000 and tagged as OE1. On Quagga A: BGP routes are injected into OSPF with a metric of 2000 and tagged as OE2 (default).
OSPF to BGP redistribution: On Cisco 3750 L3 and Quagga A, the OSPF networks are injected into BGP with the default values.
Local Preference: Cisco 3750 L3 is the preferred router to exit AS 65001 Customized local preferences are applied through route maps to the BGP incoming routes on Cisco 3750 L3 (333) and Quagga A (222).
MED. Quagga B will prefer the path via AS 65003 rather than AS 65004 to reach AS 65001. Customized MEDs are applied through route maps to the outgoing BGP routes towards AS 65005 on Cisco 2651 B (55) and Cisco 2651 C (99).
2. PICTURE
vyatta cisco case study BGP Functionalities tested:
(click on the web links to have more details about a protocol)
Interface settings OSPF - backbone area BGP Redistr. - BGP to OSPF Redistr. - OSPF to BGP Telnet access
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3. CONFIGURATIONS
You must set your Linux system correctly to launch Quagga successfully. See the Quagga tutorial for help about this. LINUX CONFIGURATIONS
Check that the zebra, ospfd and bgpd daemons are activated on Quagga A:
#vim /etc/quagga/daemons zebra=yes bgpd=yes ospfd=yes ospf6d=no ripd=no ripngd=no isisd=no
Check that the zebra and bgpd daemons are activated on Quagga B:
#vim /etc/quagga/daemons zebra=yes bgpd=yes ospfd=no ospf6d=no ripd=no ripngd=no isisd=no
If you changed your daemons files, restart the quagga service:
#vim /etc/init.d/quagga restart
Set the Quagga A hostname in the /etc/quagga/vtysh.conf file:
#vim /etc/quagga/vtysh.conf
! ! Sample ! ! service integrated-vtysh-config hostname Quagga_A username root nopassword !
Set the Quagga B hostname in the /etc/quagga/vtysh.conf file:
#vim /etc/quagga/vtysh.conf
! ! Sample ! ! service integrated-vtysh-config hostname Quagga_B username root nopassword !
Don't forget to activate the ip forwarding on the Quagga A and Quagga B routers!
ROUTERS CONFIGURATIONS
ROUTER 2651 A IOS: 12.2-23a See the entire configuration
interface FastEthernet0/1 ip address 10.0.2.99 255.255.255.0 no shutdown interface FastEthernet0/0 ip address 10.0.1.99 255.255.255.0 no shutdown interface Loopback 1 ip address 50.0.1.99 255.255.255.255 Cisco_2651_A router ospf 1 network 10.0.1.0 0.0.0.255 area 0 network 10.0.2.0 0.0.0.255 area 0 network 50.0.1.99 0.0.0.0 area 0 line vty 0 4 no login
enable secret password
SWITCH L3 3750 IOS: 12.2-25.SEE2 See the entire configuration
QUAGGA A 0.99.6 See the entire configuration
interface vlan 1 ip address 10.0.1.1 255.255.255.0 no shutdown interface FastEthernet1/0/1 switchport access vlan 1 interface eth0 ip address 10.0.2.2/24 link-detect interface vlan 2 ip address 100.0.1.1 255.255.255.0 no shutdown interface FastEthernet1/0/2 switchport access vlan 2 interface eth1 ip address 100.0.2.2/24 link-detect interface Loopback 1 ip address 50.0.1.1 255.255.255.255 interface lo ip address 50.0.1.2/32 link-detect hostname Cisco_3750_L3 router ospf 1 redistribute connected metric 1000 metric-type 1 subnets redistribute bgp 65001 metric 1000 metric-type 1 subnets network 10.0.1.0 0.0.0.255 area 0 router ospf redistribute connected metric 2000 redistribute bgp metric 2000 network 10.0.2.0/24 area 0.0.0.0 router bgp 65001 no synchronization bgp router-id 50.0.1.1 network 50.0.1.1 mask 255.255.255.255 redistribute connected redistribute ospf 1 neighbor 10.0.2.2 remote-as 65001 neighbor 100.0.1.3 remote-as 65003 neighbor 100.0.1.3 route-map r2 in no auto-summary bgp config-type cisco router bgp 65001 no synchronization bgp router-id 50.0.1.2 network 50.0.1.2 mask 255.255.255.255 redistribute connected redistribute ospf neighbor 10.0.1.1 remote-as 65001 neighbor 100.0.2.4 remote-as 65004 neighbor 100.0.2.4 route-map r2 in no auto-summary route-map r2 permit 10 set local-preference 333 route-map r2 permit 10 set local-preference 222 line vty 0 4 no login line vty no login enable secret password enable password password ip routing ip multicast-routing distributed
ROUTER 2651 B IOS: 12.2-23a See the entire configuration
QUAGGA B 0.99.6 See the entire configuration
interface FastEthernet0/0 ip address 100.0.1.3 255.255.255.0 no shutdown interface eth0 ip address 200.0.1.5/24 link-detect interface FastEthernet0/1 ip address 200.0.1.3 255.255.255.0 no shutdown interface eth1 ip address 200.0.2.5/24 link-detect interface Loopback 1 ip address 50.0.1.3 255.255.255.255 interface lo ip address 50.0.1.5/32 link-detect hostname Cisco_2651_B router bgp 65003 bgp router-id 50.0.1.3 network 50.0.1.3 mask 255.255.255.255 redistribute connected neighbor 100.0.1.1 remote-as 65001 neighbor 200.0.1.5 remote-as 65005 neighbor 200.0.1.5 route-map r3 out no auto-summary router bgp 65005 bgp router-id 50.0.1.5 network 50.0.1.5 mask 255.255.255.255 redistribute connected neighbor 200.0.1.3 remote-as 65003 neighbor 200.0.2.4 remote-as 65004 no auto-summary route-map r3 permit 10 set metric 55 line vty 0 4 no login line vty no login enable secret password enable password password
ROUTER 2651 C IOS: 12.2-23a See the entire configuration
interface FastEthernet0/0 ip address 100.0.2.4 255.255.255.0 no shutdown interface FastEthernet0/1 ip address 200.0.2.4 255.255.255.0 no shutdown interface Loopback 1 ip address 50.0.1.4 255.255.255.255 router bgp 65004 bgp router-id 50.0.1.4 network 50.0.1.4 mask 255.255.255.255 redistribute connected neighbor 100.0.2.2 remote-as 65001 neighbor 200.0.2.5 remote-as 65005 neighbor 200.0.2.5 route-map r99 out no auto-summary hostname Cisco_2651_C route-map r99 permit 10 set metric 99 line vty 0 4 no login
enable secret password
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4. SHOW COMMANDS
CISCO 2651 A CISCO 3750 L3 QUAGGA A CISCO 2651 B QUAGGA B CISCO 2651 C CISCO 2651 A
Cisco_2651_A#show ip int brief Interface IP-Address OK? Method Status Protocol FastEthernet0/0 10.0.1.99 YES NVRAM up up FastEthernet0/1 10.0.2.99 YES NVRAM up up Loopback1 50.0.1.99 YES NVRAM up up
Cisco_2651_A#show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
50.0.0.0/32 is subnetted, 6 subnets O E1 50.0.1.3 [110/1001] via 10.0.1.1, 00:37:09, FastEthernet0/0 O E2 50.0.1.2 [110/2000] via 10.0.2.2, 00:37:15, FastEthernet0/1 O E1 50.0.1.1 [110/1001] via 10.0.1.1, 00:37:15, FastEthernet0/0 O E1 50.0.1.5 [110/1001] via 10.0.1.1, 00:36:22, FastEthernet0/0 O E1 50.0.1.4 [110/1001] via 10.0.1.1, 00:35:56, FastEthernet0/0 C 50.0.1.99 is directly connected, Loopback1 100.0.0.0/24 is subnetted, 2 subnets O E1 100.0.1.0 [110/1001] via 10.0.1.1, 00:37:15, FastEthernet0/0 O E2 100.0.2.0 [110/2000] via 10.0.2.2, 00:12:48, FastEthernet0/1 O E1 200.0.1.0/24 [110/1001] via 10.0.1.1, 00:37:09, FastEthernet0/0 O E1 200.0.2.0/24 [110/1001] via 10.0.1.1, 00:36:22, FastEthernet0/0 10.0.0.0/24 is subnetted, 2 subnets C 10.0.2.0 is directly connected, FastEthernet0/1 C 10.0.1.0 is directly connected, FastEthernet0/0
Cisco_2651_A#show ip ospf database OSPF Router with ID (50.0.1.99) (Process ID 1) Router Link States (Area 0) Link ID ADV Router Age Seq# Checksum Link count 50.0.1.1 50.0.1.1 357 0x80000004 0x003417 1 50.0.1.2 50.0.1.2 555 0x80000004 0x00CC90 1 50.0.1.99 50.0.1.99 404 0x80000005 0x00236B 3 Net Link States (Area 0) Link ID ADV Router Age Seq# Checksum 10.0.1.99 50.0.1.99 404 0x80000002 0x009CCC 10.0.2.99 50.0.1.99 404 0x80000002 0x009FC7 Type-5 AS External Link States Link ID ADV Router Age Seq# Checksum Tag 50.0.1.1 50.0.1.1 357 0x80000002 0x005B84 0 50.0.1.2 50.0.1.2 502 0x80000003 0x00C3CA 0 50.0.1.3 50.0.1.1 357 0x80000002 0x00BB38 65003 50.0.1.4 50.0.1.1 357 0x80000002 0x00B141 65003 50.0.1.5 50.0.1.1 357 0x80000002 0x00A74A 65003 100.0.1.0 50.0.1.1 357 0x80000002 0x00D8D5 0 100.0.2.0 50.0.1.2 834 0x80000001 0x00441B 0 200.0.1.0 50.0.1.1 357 0x80000002 0x00342C 65003 200.0.2.0 50.0.1.1 357 0x80000002 0x002936 65003
CISCO 3750 L3
Cisco_3750_L3#show ip int brief
Interface IP-Address OK? Method Status Protocol Vlan1 10.0.1.1 YES NVRAM up up Vlan2 100.0.1.1 YES NVRAM up up FastEthernet1/0/1 unassigned YES NVRAM up up FastEthernet1/0/2 unassigned YES NVRAM up up ... ... ... ... ... ... Loopback1 50.0.1.1 YES NVRAM up up
Cisco_3750_L3#show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
50.0.0.0/32 is subnetted, 6 subnets
B 50.0.1.3 [20/0] via 100.0.1.3, 00:41:15 O E2 50.0.1.2 [110/2000] via 10.0.1.99, 00:41:20, Vlan1 C 50.0.1.1 is directly connected, Loopback1 B 50.0.1.5 [20/0] via 100.0.1.3, 00:40:27 B 50.0.1.4 [20/0] via 100.0.1.3, 00:40:01 O 50.0.1.99 [110/2] via 10.0.1.99, 00:41:20, Vlan1
100.0.0.0/24 is subnetted, 2 subnets
C 100.0.1.0 is directly connected, Vlan2 O E2 100.0.2.0 [110/2000] via 10.0.1.99, 00:16:53, Vlan1 B 200.0.1.0/24 [20/0] via 100.0.1.3, 00:41:15 B 200.0.2.0/24 [20/0] via 100.0.1.3, 00:40:27
10.0.0.0/24 is subnetted, 3 subnets
O 10.0.2.0 [110/2] via 10.0.1.99, 00:41:20, Vlan1 C 10.0.1.0 is directly connected, Vlan1 Cisco_3750_L3#show ip ospf database
OSPF Router with ID (50.0.1.1) (Process ID 1) Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count 50.0.1.1 50.0.1.1 631 0x80000004 0x003417 1 50.0.1.2 50.0.1.2 832 0x80000004 0x00CC90 1 50.0.1.99 50.0.1.99 680 0x80000005 0x00236B 3
Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum 10.0.1.99 50.0.1.99 680 0x80000002 0x009CCC 10.0.2.99 50.0.1.99 680 0x80000002 0x009FC7
Type-5 AS External Link States
Link ID ADV Router Age Seq# Checksum Tag 50.0.1.1 50.0.1.1 631 0x80000002 0x005B84 0 50.0.1.2 50.0.1.2 779 0x80000003 0x00C3CA 0 50.0.1.3 50.0.1.1 631 0x80000002 0x00BB38 65003 50.0.1.4 50.0.1.1 631 0x80000002 0x00B141 65003 50.0.1.5 50.0.1.1 631 0x80000002 0x00A74A 65003 100.0.1.0 50.0.1.1 631 0x80000002 0x00D8D5 0 100.0.2.0 50.0.1.2 1111 0x80000001 0x00441B 0 200.0.1.0 50.0.1.1 632 0x80000002 0x00342C 65003 200.0.2.0 50.0.1.1 632 0x80000002 0x002936 65003 Cisco_3750_L3#show ip bgp summary
BGP router identifier 50.0.1.1, local AS number 65001 BGP table version is 16, main routing table version 16 13 network entries using 1469 bytes of memory 24 path entries using 1248 bytes of memory 18/10 BGP path/bestpath attribute entries using 1944 bytes of memory 3 BGP AS-PATH entries using 72 bytes of memory 0 BGP route-map cache entries using 0 bytes of memory 0 BGP filter-list cache entries using 0 bytes of memory BGP using 4733 total bytes of memory BGP activity 13/0 prefixes, 24/0 paths, scan interval 60 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 10.0.2.2 4 65001 58 64 16 0 0 00:44:16 13 100.0.1.3 4 65003 54 53 16 0 0 00:45:14 6 Cisco_3750_L3#show ip bgp
BGP table version is 16, local router ID is 50.0.1.1 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
- i 10.0.1.0/24 10.0.2.99 11 100 0 ?
- > 0.0.0.0 0 32768 ?
- i 10.0.2.0/24 10.0.2.2 1 100 0 ?
- > 10.0.1.99 2 32768 ?
- i 50.0.1.1/32 10.0.2.99 1011 100 0 ?
- > 0.0.0.0 0 32768 i
r> i 50.0.1.2/32 10.0.2.2 0 100 0 i
- i i50.0.1.3/32 10.0.2.99 1011 100 0 ?
- > 100.0.1.3 0 333 0 65003 i
- i 50.0.1.4/32 10.0.2.99 1011 100 0 ?
- > 100.0.1.3 333 0 65003 65005 65004 i
- i 50.0.1.5/32 10.0.2.99 1011 100 0 ?
- > 100.0.1.3 333 0 65003 65005 i
- i 50.0.1.99/32 10.0.2.99 11 100 0 ?
- > 10.0.1.99 2 32768 ?
- i 100.0.1.0/24 10.0.2.99 1011 100 0 ?
- 100.0.1.3 0 333 0 65003 ?
- > 0.0.0.0 0 32768 ?
r> i 100.0.2.0/24 10.0.2.2 1 100 0 ?
- i 200.0.1.0 10.0.2.99 1011 100 0 ?
- > 100.0.1.3 0 333 0 65003 ?
- i 200.0.2.0 10.0.2.99 1011 100 0 ?
- > 100.0.1.3 333 0 65003 65005 ?
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QUAGGA A
Quagga_A#show interface description
Interface Status Protocol Description eth0 up up eth1 up up lo up up Quagga_A#show ip route
Codes: K - kernel route, C - connected, S - static, R - RIP, O - OSPF,
I - ISIS, B - BGP, > - selected route, * - FIB route
O>* 10.0.1.0/24 [110/11] via 10.0.2.99, eth0, 01:11:01 O 10.0.2.0/24 [110/10] is directly connected, eth0, 01:11:48 C>* 10.0.2.0/24 is directly connected, eth0 O>* 50.0.1.1/32 [110/1011] via 10.0.2.99, eth0, 01:10:16 C>* 50.0.1.2/32 is directly connected, lo O>* 50.0.1.3/32 [110/1011] via 10.0.2.99, eth0, 01:10:02 O>* 50.0.1.4/32 [110/1011] via 10.0.2.99, eth0, 01:08:48 O>* 50.0.1.5/32 [110/1011] via 10.0.2.99, eth0, 01:09:14 O>* 50.0.1.99/32 [110/11] via 10.0.2.99, eth0, 01:11:01 O>* 100.0.1.0/24 [110/1011] via 10.0.2.99, eth0, 01:10:16 C>* 100.0.2.0/24 is directly connected, eth1 C>* 127.0.0.0/8 is directly connected, lo O>* 200.0.1.0/24 [110/1011] via 10.0.2.99, eth0, 01:10:02 O>* 200.0.2.0/24 [110/1011] via 10.0.2.99, eth0, 01:09:14 Quagga_A (Linux level)#route -n
Destination Gateway Genmask Flags Metric Ref Use Iface 50.0.1.1 10.0.2.99 255.255.255.255 UGH 1011 0 0 eth0 50.0.1.99 10.0.2.99 255.255.255.255 UGH 11 0 0 eth0 50.0.1.3 10.0.2.99 255.255.255.255 UGH 1011 0 0 eth0 50.0.1.5 10.0.2.99 255.255.255.255 UGH 1011 0 0 eth0 50.0.1.4 10.0.2.99 255.255.255.255 UGH 1011 0 0 eth0 10.0.1.0 10.0.2.99 255.255.255.0 UG 11 0 0 eth0 10.0.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 100.0.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 200.0.1.0 10.0.2.99 255.255.255.0 UG 1011 0 0 eth0 200.0.2.0 10.0.2.99 255.255.255.0 UG 1011 0 0 eth0 100.0.1.0 10.0.2.99 255.255.255.0 UG 1011 0 0 eth0 Quagga_A#show ip ospf database
OSPF Router with ID (50.0.1.2) Router Link States (Area 0.0.0.0)
Link ID ADV Router Age Seq# CkSum Link count 50.0.1.1 50.0.1.1 292 0x80000005 0x3218 1 50.0.1.2 50.0.1.2 693 0x80000005 0xca91 1 50.0.1.99 50.0.1.99 311 0x80000006 0x216c 3
Net Link States (Area 0.0.0.0) ADV Router CkSum
10.0.1.99 50.0.1.99 0x80000003 0x9acd 10.0.2.99 50.0.1.99 0x80000003 0x9dc8
AS External Link States
Link ID ADV Router Age Seq# CkSum Route 50.0.1.1 50.0.1.1 292 0x80000003 0x5985 E1 50.0.1.1/32 [0x0] 50.0.1.2 50.0.1.2 611 0x80000004 0xc1cb 50.0.1.2/32 [0x0] 50.0.1.3 50.0.1.1 292 0x80000003 0xb939 50.0.1.3/32 [0xfdeb] 50.0.1.4 50.0.1.1 292 0x80000003 0xaf42 50.0.1.4/32 [0xfdeb] 50.0.1.5 50.0.1.1 292 0x80000003 0xa54b 50.0.1.5/32 [0xfdeb] 100.0.1.0 50.0.1.1 292 0x80000003 0xd6d6 100.0.1.0/24 [0x0] 100.0.2.0 50.0.1.2 1431 0x80000002 0x421c 100.0.2.0/24 [0x0] 200.0.1.0 50.0.1.1 292 0x80000003 0x322d 200.0.1.0/24 [0xfdeb] 200.0.2.0 50.0.1.1 292 0x80000003 0x2737 200.0.2.0/24 [0xfdeb] Quagga_A#show ip bgp summary
BGP router identifier 50.0.1.2, local AS number 65001 RIB entries 25, using 1600 bytes of memory Peers 2, using 5024 bytes of memory
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 10.0.1.1 4 65001 89 85 0 0 0 01:11:27 10 100.0.2.4 4 65004 57 53 0 0 0 00:46:37 5
Total number of neighbors 2 Quagga_A#show ip bgp
BGP table version is 0, local router ID is 50.0.1.2 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, R Removed
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
- i 10.0.1.0/24 10.0.1.1 0 100 0 ?
- > 10.0.2.99 11 32768 ?
- i 10.0.2.0/24 10.0.1.99 2 100 0 ?
- > 0.0.0.0 1 32768 ?
- i 50.0.1.1/32 10.0.1.1 0 100 0 i
- > 10.0.2.99 1011 32768 ?
- 50.0.1.2/32 0.0.0.0 1 32768 ?
- > 0.0.0.0 0 32768 i
- > 50.0.1.3/32 10.0.2.99 1011 32768 ?
- i 100.0.1.3 0 333 0 65003 i
- 50.0.1.4/32 100.0.2.4 0 222 0 65004 i
- > 10.0.2.99 1011 32768 ?
- i 100.0.1.3 0 333 0 65003 65005 65004 i
- 50.0.1.5/32 100.0.2.4 222 0 65004 65005 i
- i 100.0.1.3 0 333 0 65003 65005 i
- > 10.0.2.99 1011 32768 ?
- i 50.0.1.99/32 10.0.1.99 2 100 0 ?
- > 10.0.2.99 11 32768 ?
- i 100.0.1.0/24 10.0.1.1 0 100 0 ?
- > 10.0.2.99 1011 32768 ?
- 100.0.2.0/24 100.0.2.4 0 222 0 65004 ?
- > 0.0.0.0 1 32768 ?
- 200.0.1.0 100.0.2.4 222 0 65004 65005 ?
- > 10.0.2.99 1011 32768 ?
- i 100.0.1.3 0 333 0 65003 ?
- 200.0.2.0 100.0.2.4 0 222 0 65004 ?
- > 10.0.2.99 1011 32768 ?
- i 100.0.1.3 0 333 0 65003 65005 ?
Let's look at the weight effect on the 50.1.0.3 network (see above): There are two routes for 50.0.1.3; which one will be chosen? The weights are different so the elected route (indicated with the ">" character) will have the highest weight (32768).
Let's look at the local preference effect on the 50.1.0.5 network (see above): There are two routes for 50.0.1.5; which one will be chosen? The weights are equals -> the local preferences are different so the route (indicated with the ">" character) with the highest local preference (333) will be chosen.
See details about the BGP path selection process.
Quagga_A#show route-map r2
OSPF: route-map r2, permit, sequence 10
Match clauses: Set clauses: Call clause: Action: Exit routemap
BGP: route-map r2, permit, sequence 10
Match clauses: Set clauses: local-preference 222 Call clause: Action: Exit routemap
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CISCO 2651 B
Cisco_2651_B#show ip interface brief
Interface IP-Address OK? Method Status Protocol FastEthernet0/1 100.0.1.3 YES NVRAM up up FastEthernet0/1 200.0.1.3 YES NVRAM up up Loopback1 50.0.1.3 YES NVRAM up up Cisco_2651_B#show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
50.0.0.0/32 is subnetted, 6 subnets
C 50.0.1.3 is directly connected, Loopback1 B 50.0.1.2 [20/0] via 100.0.1.1, 00:46:33 B 50.0.1.1 [20/0] via 100.0.1.1, 00:47:02 B 50.0.1.5 [20/0] via 200.0.1.5, 00:46:30 B 50.0.1.4 [20/0] via 200.0.1.5, 00:46:00 B 50.0.1.99 [20/2] via 100.0.1.1, 00:47:02
100.0.0.0/24 is subnetted, 2 subnets
C 100.0.1.0 is directly connected, FastEthernet0/0 B 100.0.2.0 [20/0] via 100.0.1.1, 00:22:34 C 200.0.1.0/24 is directly connected, FastEthernet0/1 B 200.0.2.0/24 [20/1] via 200.0.1.5, 00:46:30
10.0.0.0/24 is subnetted, 3 subnets
B 10.0.2.0 [20/2] via 100.0.1.1, 00:47:02 B 10.0.1.0 [20/0] via 100.0.1.1, 00:47:03 Cisco_2651_B#show ip bgp summary
BGP router identifier 50.0.1.3, local AS number 65003 BGP table version is 14, main routing table version 14 13 network entries using 1261 bytes of memory 16 path entries using 576 bytes of memory 11 BGP path attribute entries using 660 bytes of memory 3 BGP AS-PATH entries using 72 bytes of memory 0 BGP route-map cache entries using 0 bytes of memory 0 BGP filter-list cache entries using 0 bytes of memory BGP using 2569 total bytes of memory BGP activity 13/0 prefixes, 16/0 paths, scan interval 60 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 100.0.1.1 4 65001 56 57 14 0 0 00:48:56 8 200.0.1.5 4 65005 57 58 14 0 0 00:47:26 5 Cisco_2651_B#show ip bgp
BGP table version is 16, local router ID is 50.0.1.3 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, R Removed
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
- > 10.0.1.0/24 100.0.1.1 0 0 65001 ?
- 200.0.1.5 0 65005 65004 65001 ?
- > 10.0.2.0/24 100.0.1.1 2 0 65001 ?
- 200.0.1.5 0 65005 65004 65001 ?
- > 50.0.1.1/32 100.0.1.1 0 0 65001 i
- > 50.0.1.2/32 100.0.1.1 0 65001 i
- 200.0.1.5 0 65005 65004 65001 i
- > 50.0.1.3/32 0.0.0.0 0 32768 i
- > 50.0.1.4/32 100.0.1.1 0 65001 65004 i
- 200.0.1.5 0 65005 65004 i
- > 50.0.1.5/32 200.0.1.5 0 0 65005 i
- > 50.0.1.99/32 100.0.1.1 2 0 65001 ?
- 200.0.1.5 0 65005 65004 65001 ?
- > 100.0.1.0/24 0.0.0.0 0 32768 ?
- 100.0.1.1 0 0 65001 ?
- > 100.0.2.0/24 100.0.1.1 0 65001 ?
- 200.0.1.5 0 65005 65004 ?
- > 200.0.1.0 0.0.0.0 0 32768 ?
- 200.0.1.5 1 0 65005 ?
- > 200.0.2.0 200.0.1.5 1 0 65005 ?
Let's look at the AS path effect on the 10.0.2.0 network (in red above): There are two routes for 10.0.2.0; which one will be chosen?
The weights are equals (0) -> the local preferences are not set -> The path lengths are different. This means that the elected route (indicated with the ">" character) will have the shortest path (1).
See details about the BGP path selection process.
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QUAGGA B
Quagga_B#show interface description
Interface Status Protocol Description eth0 up up eth1 up up lo up up Quagga_B#show ip route
Codes: K - kernel route, C - connected, S - static, R - RIP, O - OSPF,
I - ISIS, B - BGP, > - selected route, * - FIB route
B>* 10.0.1.0/24 [20/55] via 200.0.1.3, eth0, 01:14:47 B>* 10.0.2.0/24 [20/55] via 200.0.1.3, eth0, 01:14:47 B>* 50.0.1.1/32 [20/55] via 200.0.1.3, eth0, 01:14:47 B>* 50.0.1.2/32 [20/55] via 200.0.1.3, eth0, 01:14:47 B>* 50.0.1.3/32 [20/55] via 200.0.1.3, eth0, 01:14:47 B>* 50.0.1.4/32 [20/99] via 200.0.2.4, eth1, 01:14:45 C>* 50.0.1.5/32 is directly connected, lo B>* 50.0.1.99/32 [20/55] via 200.0.1.3, eth0, 01:14:47 B>* 100.0.1.0/24 [20/55] via 200.0.1.3, eth0, 01:14:47 B>* 100.0.2.0/24 [20/99] via 200.0.2.4, eth1, 00:50:45 C>* 127.0.0.0/8 is directly connected, lo C>* 200.0.1.0/24 is directly connected, eth0 C>* 200.0.2.0/24 is directly connected, eth1 Quagga_B#show ip bgp summary
BGP router identifier 50.0.1.5, local AS number 65005 RIB entries 25, using 1600 bytes of memory Peers 2, using 5024 bytes of memory
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 200.0.1.3 4 65003 85 85 0 0 0 01:16:00 10 200.0.2.4 4 65004 84 90 0 0 0 01:15:59 11
Total number of neighbors 2 Quagga_B#show ip bgp
BGP table version is 0, local router ID is 50.0.1.5 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, R Removed
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
- 10.0.1.0/24 200.0.2.4 99 0 65004 65001 ?
- > 200.0.1.3 55 0 65003 65001 ?
- 10.0.2.0/24 200.0.2.4 99 0 65004 65001 ?
- > 200.0.1.3 55 0 65003 65001 ?
- 50.0.1.1/32 200.0.2.4 99 0 65004 65001 ?
- > 200.0.1.3 55 0 65003 65001 i
- 50.0.1.2/32 200.0.2.4 99 0 65004 65001 i
- > 200.0.1.3 55 0 65003 65001 i
- 50.0.1.3/32 200.0.2.4 99 0 65004 65001 ?
- > 200.0.1.3 55 0 65003 i
- > 50.0.1.4/32 200.0.2.4 99 0 65004 i
- 50.0.1.5/32 0.0.0.0 1 32768 ?
- > 0.0.0.0 0 32768 i
- 50.0.1.99/32 200.0.2.4 99 0 65004 65001 ?
- > 200.0.1.3 55 0 65003 65001 ?
- 100.0.1.0/24 200.0.2.4 99 0 65004 65001 ?
- > 200.0.1.3 55 0 65003 ?
- > 100.0.2.0/24 200.0.2.4 99 0 65004 ?
- 200.0.1.3 55 0 65003 65001 ?
- 200.0.1.0 200.0.1.3 55 0 65003 ?
- > 0.0.0.0 1 32768 ?
- 200.0.2.0 200.0.2.4 99 0 65004 ?
- > 0.0.0.0 1 32768 ?
Let's look at the MED effect on the 10.0.1.0 network (in red above): There are two routes for 10.0.1.0; which one will be chosen?
The weights are equal (0) -> the local preferences are not set -> The path lengthsare equal (2) -> The origine codes are equal ("?" character) -> the MED are differrent. It means that the elected route (indicated with the ">" character) will have the lowest MED (55).
See details about the BGP path selection process.
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CISCO 2651 C
Cisco_2651_C#show ip interface brief
Interface IP-Address OK? Method Status Protocol FastEthernet0/1 100.0.2.4 YES NVRAM up up FastEthernet0/1 200.0.2.4 YES NVRAM up up Loopback1 50.0.1.4 YES NVRAM up up Cisco_2651_C#show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
50.0.0.0/32 is subnetted, 6 subnets
B 50.0.1.3 [20/1011] via 100.0.2.2, 00:41:28 B 50.0.1.2 [20/0] via 100.0.2.2, 00:41:28 B 50.0.1.1 [20/1011] via 100.0.2.2, 00:41:28 B 50.0.1.5 [20/0] via 200.0.2.5, 01:05:46 C 50.0.1.4 is directly connected, Loopback1 B 50.0.1.99 [20/11] via 100.0.2.2, 00:41:29
100.0.0.0/24 is subnetted, 2 subnets
B 100.0.1.0 [20/1011] via 100.0.2.2, 00:41:28 C 100.0.2.0 is directly connected, Ethernet0/0 B 200.0.1.0/24 [20/1] via 200.0.2.5, 01:05:46 C 200.0.2.0/24 is directly connected, Ethernet0/1
10.0.0.0/24 is subnetted, 3 subnets
B 10.0.2.0 [20/1] via 100.0.2.2, 00:41:28 B 10.0.1.0 [20/11] via 100.0.2.2, 00:41:30 Cisco_2651_C#show ip bgp summary
BGP router identifier 50.0.1.4, local AS number 65004 BGP table version is 24, main routing table version 24 13 network entries and 26 paths using 2197 bytes of memory 12 BGP path attribute entries using 624 bytes of memory 4 BGP AS-PATH entries using 96 bytes of memory 0 BGP route-map cache entries using 0 bytes of memory 0 BGP filter-list cache entries using 0 bytes of memory BGP activity 16/26 prefixes, 31/2 paths, scan interval 15 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 100.0.2.2 4 65001 49 54 24 0 0 00:42:26 12 200.0.2.5 4 65005 81 76 24 0 0 01:06:44 11 Cisco_2651_C#show ip bgp
BGP table version is 0, local router ID is 50.0.1.5 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, R Removed
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
- > 10.0.1.0/24 100.0.2.2 11 0 65001 ?
- 200.0.2.5 0 65005 65003 65001 ?
- > 10.0.2.0/24 100.0.2.2 0 0 65001 ?
- 200.0.2.5 0 65005 65003 65001 ?
- > 50.0.1.1/32 100.0.2.2 1011 0 65001 ?
- 200.0.2.5 0 65005 65003 65001 i
- > 50.0.1.2/32 100.0.2.2 0 0 65001 i
- 200.0.2.5 0 65005 65003 65001 i
- > 50.0.1.3/32 100.0.2.2 1011 0 65001 ?
- 200.0.2.5 0 65005 65003 i
- > 50.0.1.4/32 0.0.0.0 0 32768 i
- 50.0.1.5/32 100.0.2.2 1011 0 65001 ?
- > 200.0.2.5 0 0 65005 i
- > 50.0.1.99/32 100.0.2.2 11 0 65001 ?
- 200.0.2.5 0 65005 65003 65001 ?
- > 100.0.1.0/24 100.0.2.2 1011 0 65001 ?
- 200.0.2.5 0 65005 65003 ?
- 100.0.2.0/24 100.0.2.2 1 0 65001 ?
- > 200.0.2.5 0 32768 ?
- 200.0.1.0 100.0.2.2 1011 0 65001 ?
- > 200.0.2.5 1 0 65005 ?
- 200.0.2.0 100.0.2.2 1011 0 65001 ?
- 200.0.2.5 1 0 65005 ?
- > 0.0.0.0 0 32768 ?
Let's look at the origin code effect on the 50.0.1.5 network (in red above): There are two routes for 50.0.1.5; which one will be chosen?
The weights are equal (0) -> the local preferences are not set -> The path lengths are equal (1) -> The origin codes are different. It means that the elected route (indicated with the ">" character) will have the lowest origin code (i).
See details about the BGP path selection process.
Cisco_2651_C#show route-map
route-map r99, permit, sequence 10
Match clauses: Set clauses: metric 99 Policy routing matches: 0 packets, 0 bytes
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5. FAILOVER SCENARIO
The goal is to power off Switch 3750 L3 and see the routing tables changes on Cisco 2651 A and Quagga A. Cisco 2651 A should always be able to reach Quagga B but via Quagga A instead of Switch 3750 L3.
Paths comparison from Cisco 2651 A to Quagga B: (recursive ping from Cisco 2651 A to Quagga B)
10.0.1.99 100.0.1.1 200.0.1.3 50.0.1.5 50.0.1.5 100.0.1.3 10.0.1.1 10.0.1.99 10.0.2.99 100.0.2.2 200.0.2.4 50.0.1.5 50.0.1.5 100.0.2.4 10.0.2.2 10.0.2.99 Cisco 2651 A - Best routes comparison: ("show ip route")
50.0.0.0/32 is subnetted, 6 subnets
O E1 50.0.1.1 [110/1001] via 10.0.1.1, FastEth0/0 O E2 50.0.1.2 [110/2000] via 10.0.2.2, FastEth0/1 O E1 50.0.1.3 [110/1001] via 10.0.1.1, FastEth0/0 O E1 50.0.1.5 [110/1001] via 10.0.1.1, FastEth0/0 O E1 50.0.1.4 [110/1001] via 10.0.1.1, FastEth0/0 C 50.0.1.99 is directly connected, Loopback1
100.0.0.0/24 is subnetted, 2 subnets
O E1 100.0.1.0 [110/1001] via 10.0.1.1, FastEth0/0 O E2 100.0.2.0 [110/2000] via 10.0.2.2, FastEth0/1 O E1 200.0.1.0/24 [110/2000] via 10.0.2.2, FastEth0/1 O E1 200.0.2.0/24 [110/2000] via 10.0.2.2, FastEth0/1
10.0.0.0/24 is subnetted, 2subnets
C 10.0.1.0 is directly connected, FastEth0/0 C 10.0.2.0 is directly connected, FastEth0/1
50.0.0.0/32 is subnetted, 5 subnets ------------------------
O E2 50.0.1.2 [110/2000] via 10.0.2.2, FastEth0/1 O E2 50.0.1.3 [110/2000] via 10.0.2.2, FastEth0/1 O E2 50.0.1.4 [110/2000] via 10.0.2.2, FastEth0/1 O E2 50.0.1.5 [110/2000] via 10.0.2.2, FastEth0/1 C 50.0.1.99 is directly connected, Loopback1
100.0.0.0/24 is subnetted, 2 subnets
O E2 100.0.1.0 [110/2000] via 10.0.2.2, FastEth0/1 O E2 100.0.2.0 [110/2000] via 10.0.2.2, FastEth0/1 O E2 200.0.1.0/24 [110/2000] via 10.0.2.2, FastEth0/1 O E2 200.0.2.0/24 [110/2000] via 10.0.2.2, FastEth0/1
10.0.0.0/24 is subnetted, 1 subnets ------------------------
C 10.0.2.0 is directly connected, FastEth0/1 Quagga A - Best routes comparison: ("show ip route")
C>* 10.0.2.0/24 is directly connected, eth0 C>* 100.0.2.0/24 is directly connected, eth1 C>* 50.0.1.2/32 is directly connected, lo O 10.0.2.0/24 [110/10] is directly connected, eth0 O>* 10.0.1.0/24 [110/11] via 10.0.2.99, eth0 O>* 50.0.1.1/32 [110/1011] via 10.0.2.99, eth0 O>* 50.0.1.3/32 [110/1011] via 10.0.2.99, eth0 O>* 50.0.1.4/32 [110/1011] via 10.0.2.99, eth0 O>* 50.0.1.5/32 [110/1011] via 10.0.2.99, eth0 O>* 50.0.1.99/32 [110/11] via 10.0.2.99, eth0 O>* 100.0.1.0/24 [110/1011] via 10.0.2.99, eth0 O>* 200.0.1.0/24 [110/1011] via 10.0.2.99, eth0 O>* 200.0.2.0/24 [110/1011] via 10.0.2.99, eth0
C>* 10.0.2.0/24 is directly connected, eth0 C>* 100.0.2.0/24 is directly connected, eth1 C>* 50.0.1.2/32 is directly connected, lo O 10.0.2.0/24 [110/10] is directly connected, eth0
------------------------ ------------------------
B>* 50.0.1.3/32 [20/0] via 100.0.2.4, eth1 B>* 50.0.1.4/32 [20/0] via 100.0.2.4, eth1 B>* 50.0.1.5/32 [20/0] via 100.0.2.4, eth1 O>* 50.0.1.99/32 [110/11] via 10.0.2.99, eth0
------------------------
B>* 200.0.1.0/24 [20/0] via 100.0.2.4, eth1 B>* 200.0.2.0/24 [20/0] via 100.0.2.4, eth1 Quagga A - BGP routes comparison: ("show ip bgp")
- i 10.0.1.0/24 10.0.1.1 0 100 0 ?
- > 10.0.2.99 11 32768 ?
- i 10.0.2.0/24 10.0.1.99 2 100 0 ?
- > 0.0.0.0 1 32768 ?
- i 50.0.1.1/32 10.0.1.1 0 100 0 i
- > 10.0.2.99 1011 32768 ?
- 50.0.1.2/32 0.0.0.0 1 32768 ?
- > 0.0.0.0 0 32768 i
- > 50.0.1.3/32 10.0.2.99 1011 32768 ?
- i 100.0.1.3 0 333 0 65003 i
- 50.0.1.4/32 100.0.2.4 0 222 0 65004 i
- > 10.0.2.99 1011 32768 ?
- i 100.0.1.3 0 333 0 65003 65005 65004 i
- 50.0.1.5/32 100.0.2.4 222 0 65004 65005 i
- i 100.0.1.3 0 333 0 65003 65005 i
- > 10.0.2.99 1011 32768 ?
- i 50.0.1.99/32 10.0.1.99 2 100 0 ?
- > 10.0.2.99 11 32768 ?
- i 100.0.1.0/24 10.0.1.1 0 100 0 ?
- > 10.0.2.99 1011 32768 ?
- 100.0.2.0/24 100.0.2.4 0 222 0 65004 ?
- > 0.0.0.0 1 32768 ?
- 200.0.1.0 100.0.2.4 222 0 65004 65005 ?
- > 10.0.2.99 1011 32768 ?
- i 100.0.1.3 0 333 0 65003 ?
- 200.0.2.0 100.0.2.4 0 222 0 65003 ?
- > 10.0.2.99 1011 32768 ?
- i 100.0.1.3 0 333 0 65003 65005 ?
- > i 10.0.1.0/24 10.0.1.1 0 100 0 ?
------------------------
- i 10.0.2.0/24 10.0.1.99 2 100 0 ?
- > 0.0.0.0 1 32768 ?
- > i 50.0.1.1/32 10.0.1.1 0 100 0 i
------------------------
- 50.0.1.2/32 0.0.0.0 1 32768 ?
- > 0.0.0.0 0 32768 i
- > 50.0.1.3/32 100.0.2.4 222 0 65004 65005 65003 i
------------------------
- > 50.0.1.4/32 100.0.2.4 0 222 0 65004 i
------------------------ ------------------------
- > 50.0.1.5/32 100.0.2.4 222 0 65004 65005 i
------------------------ ------------------------
- i 50.0.1.99/32 10.0.1.99 2 100 0 ?
- > 10.0.2.99 11 32768 ?
------------------------ ------------------------
- 100.0.2.0/24 100.0.2.4 0 222 0 65004 ?
- > 0.0.0.0 1 32768 ?
- > 200.0.1.0 100.0.2.4 222 0 65004 65005 ?
------------------------ ------------------------
- > 200.0.2.0 100.0.2.4 0 222 0 65004 ?
------------------------ ------------------------
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