This video and the included configs/diagrams show how to have failover with VM infrastructure/SAN replication in multiple datacenters. This basically leverages the power of BGP to move our public addressing. BGP is the ONLY choice to have addressing seamlessly migrate from one site to another…it is the protocol that the Internet happens to run on 😉
We use a combination of Cisco equipment with BGP(using prepending and filtering) and VRRP, though the below configs show HSRP instead(the Cisco proprietary version of VRRP). BGP does our public advertising to the internet while VRRP provides us gateway redundancy inside our network.
We also stretch the VM L2 subnets across the datacenters so we can have seamless VM migration from one location to the other.
Here’s the diagrams that go along with the video:
.Here’s the video(only about 10 minutes long):
Here are the router configs:
Internet
hostname Internet
!
interface FastEthernet0/0
description houston
ip address 11.11.11.2 255.255.255.252
duplex auto
speed auto
!
interface FastEthernet0/1
description bryan
ip address 12.12.12.2 255.255.255.252
duplex auto
speed auto
!
interface FastEthernet1/0
ip address 10.0.0.1 255.255.255.0
duplex auto
speed auto
!
router bgp 1
bgp log-neighbor-changes
neighbor 11.11.11.1 remote-as 2
neighbor 11.11.11.1 version 4
neighbor 12.12.12.1 remote-as 2
neighbor 12.12.12.1 version 4
!
address-family ipv4
neighbor 11.11.11.1 activate
neighbor 11.11.11.1 default-originate
neighbor 12.12.12.1 activate
neighbor 12.12.12.1 default-originate
no auto-summary
no synchronization
network 20.0.0.0 mask 255.255.255.0
exit-address-family
!Bryan
!
hostname bryan
!
!
ip subnet-zero
ip routing
!
!
spanning-tree extend system-id
!
!
!
interface FastEthernet0/1
switchport trunk encapsulation dot1q
switchport mode trunk
no ip address
!
interface FastEthernet0/2
no switchport
ip address 12.12.12.1 255.255.255.252
!
interface FastEthernet0/3
description [failover p2p]
switchport trunk encapsulation dot1q
switchport mode trunk
no ip address
!
interface FastEthernet0/47
switchport access vlan 20
switchport mode access
no ip address
spanning-tree portfast
!
interface FastEthernet0/48
switchport access vlan 10
switchport mode access
no ip address
spanning-tree portfast
!
interface Vlan1
no ip address
shutdown
!
interface Vlan10
description [Houston Primary]
ip address 192.168.1.3 255.255.255.0
no ip redirects
standby preempt delay minimum 30
standby 10 ip 192.168.1.1
standby 10 preempt
standby 10 track FastEthernet0/2 20
!
interface Vlan20
description [Bryan Primary]
ip address 192.168.2.2 255.255.255.0
no ip redirects
standby preempt delay minimum 30
standby 20 ip 192.168.2.1
standby 20 priority 105
standby 20 preempt
standby 20 track FastEthernet0/2 20
!
router bgp 2
no synchronization
bgp log-neighbor-changes
network 1.1.1.0 mask 255.255.255.0
network 2.2.2.0 mask 255.255.255.0
network 192.168.1.0
network 192.168.2.0
neighbor 12.12.12.2 remote-as 1
neighbor 12.12.12.2 version 4
neighbor 12.12.12.2 soft-reconfiguration inbound
neighbor 12.12.12.2 prefix-list in in
neighbor 12.12.12.2 route-map out out
no auto-summary
!
ip classless
ip route 1.1.1.0 255.255.255.0 Null0 250
ip route 2.2.2.0 255.255.255.0 Null0
!
!
!
ip prefix-list in seq 5 permit 0.0.0.0/0
ip prefix-list in seq 15 deny 0.0.0.0/0 le 32
!
ip prefix-list out seq 5 permit 192.168.2.0/24
ip prefix-list out seq 10 deny 0.0.0.0/0 le 32
!
ip prefix-list out-prepend seq 5 permit 192.168.1.0/24
ip prefix-list out-prepend seq 10 deny 0.0.0.0/0 le 32
!
route-map out permit 10
match ip address prefix-list out
set origin igp
!
route-map out permit 20
match ip address prefix-list out-prepend
set as-path prepend 2 2 2 2
!Houston
!
hostname hou
!
!
ip subnet-zero
ip routing
!
!
interface FastEthernet0/1
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/2
no switchport
ip address 11.11.11.1 255.255.255.252
!
interface FastEthernet0/3
description [failover p2p]
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/47
switchport access vlan 20
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/48
switchport access vlan 10
switchport mode access
spanning-tree portfast
!
interface Vlan1
no ip address
shutdown
!
interface Vlan10
description [Houston Primary]
ip address 192.168.1.2 255.255.255.0
standby preempt delay minimum 30
standby 10 ip 192.168.1.1
standby 10 priority 105
standby 10 preempt
standby 10 track FastEthernet0/2 20
!
interface Vlan20
description [Bryan Primary]
ip address 192.168.2.3 255.255.255.0
standby preempt delay minimum 30
standby 20 ip 192.168.2.1
standby 20 preempt
standby 20 track FastEthernet0/2 20
!
router bgp 2
bgp log-neighbor-changes
neighbor 11.11.11.2 remote-as 1
neighbor 11.11.11.2 version 4
!
address-family ipv4
neighbor 11.11.11.2 activate
neighbor 11.11.11.2 soft-reconfiguration inbound
neighbor 11.11.11.2 prefix-list in in
neighbor 11.11.11.2 route-map out out
no auto-summary
no synchronization
network 1.1.1.0 mask 255.255.255.0
network 2.2.2.0 mask 255.255.255.0
network 192.168.1.0
network 192.168.2.0
exit-address-family
!
ip classless
ip route 1.1.1.0 255.255.255.0 Null0
ip route 2.2.2.0 255.255.255.0 Null0 250
!
ip prefix-list in seq 5 permit 0.0.0.0/0
ip prefix-list in seq 15 deny 0.0.0.0/0 le 32
!
ip prefix-list out seq 5 permit 192.168.1.0/24
ip prefix-list out seq 10 deny 0.0.0.0/0 le 32
!
ip prefix-list out-prepend seq 5 permit 192.168.2.0/24
ip prefix-list out-prepend seq 10 deny 0.0.0.0/0 le 32
route-map out permit 10
match ip address prefix-list out
set origin igp
!
route-map out permit 20
match ip address prefix-list out-prepend
set as-path prepend 2 2 2 2
!
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