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New Member

Problem with HSRP routers occasionally becoming active-active

I have an issue with HSRP routers occasionally becoming active-active in our branch networks.  

The site has two 1921 routers with HWIC-4ESW each and connect to Catalyst 2960 Access switches.  Router1 is normally the active router and Router2  the standby router.

Occasionally, Router1 loses connectivity to the access switch, so Router 2 does not get any HSRP response from Router 1 and becomes active router as well, creating an active-active scenario.

Router1 port Fa0/0/0 stays forwarding though it is unable to reach Access switch 1.  If I run show CDP neighbour, the router is unable to see the Switch1 (CDP is running on both router and switch). 

Access Switch1 port F0/1 is also forwarding but unable to ping router 1.  It can see Router 1 when I run show CDP neighbour.

If I bounce the ports, they will see each other for a about 45 seconds then drop the connection again.

The only way to restore the connection and fix the HSRP active-active router scenario is to reboot Router 1.

This happens is randomly in several branches with the same topology once to twice a month.  The configuration has worked fine with no issues for over a year. I am not sure if this has anything to do with BGP  since this issue started after we implemented BGP routing with our ISPs.

Everyone's tags (1)
3 REPLIES
VIP Super Bronze

BGP with ISP should not

BGP with ISP should not affect your HSRP.

Curios why you have configured preemption on both routers? Usually, you need preemption on the router that has higher priority

(in this case router-1).

Also, can you post your BGP config form both routers?

HTH

 

.

New Member

ROUTER1#sh run | section

ROUTER1#sh run | section bgp
router bgp 65015
 bgp router-id 192.168.30.15
 bgp log-neighbor-changes
 network 172.20.120.0 mask 255.255.255.0
 network 172.20.121.0 mask 255.255.255.0
 network 172.20.122.0 mask 255.255.255.0
 network 172.20.123.0 mask 255.255.255.0
 network 172.20.124.0 mask 255.255.255.0
 network 172.20.125.0 mask 255.255.255.0
 network 172.20.126.0 mask 255.255.255.0
 network 172.20.127.0 mask 255.255.255.0
 network 192.168.30.15 mask 255.255.255.255
 aggregate-address 172.20.120.0 255.255.248.0 summary-only
 neighbor 10.92.0.121 remote-as 7543
 neighbor 10.92.0.121 send-community extended
 neighbor 10.92.0.121 soft-reconfiguration inbound
 neighbor 10.92.0.121 route-map bgp-ISP1-import in
 neighbor 10.92.0.121 route-map bgp-ISP1-export out
 neighbor 172.20.127.252 remote-as 65015
 neighbor 172.20.127.252 next-hop-self
 neighbor 172.20.127.252 send-community extended
 neighbor 172.20.127.252 soft-reconfiguration inbound
ip prefix-list bgp-ALL seq 10 permit 0.0.0.0/0 le 32
ip prefix-list bgp-Advertise-ISP1 seq 10 permit 172.20.120.0/21 le 25
ip prefix-list bgp-Advertise-ISP1 seq 15 permit 192.168.30.15/32
ip prefix-list bgp-Advertise-ISP1 seq 20 permit 192.168.40.15/32
route-map bgp-ISP1-import permit 10
 match ip address prefix-list bgp-ALL
 set local-preference 200
route-map bgp-ISP1-export permit 10
 match ip address prefix-list bgp-Advertise-ISP1
route-map bgp-ISP1-export deny 20
 match ip address prefix-list bgp-ALL
snmp-server enable traps bgp

 

ROUTER2#sh run | section bgp
router bgp 65015
 bgp router-id 192.168.40.15
 bgp log-neighbor-changes
 network 172.20.120.0 mask 255.255.255.0
 network 172.20.121.0 mask 255.255.255.0
 network 172.20.122.0 mask 255.255.255.0
 network 172.20.123.0 mask 255.255.255.0
 network 172.20.124.0 mask 255.255.255.0
 network 172.20.125.0 mask 255.255.255.0
 network 172.20.126.0 mask 255.255.255.0
 network 172.20.127.0 mask 255.255.255.0
 network 192.168.40.15 mask 255.255.255.255
 aggregate-address 172.20.120.0 255.255.248.0 summary-only
 neighbor 10.92.20.121 remote-as 7545
 neighbor 10.92.20.121 send-community extended
 neighbor 10.92.20.121 soft-reconfiguration inbound
 neighbor 10.92.20.121 route-map bgp-ISP2-import in
 neighbor 10.92.20.121 route-map bgp-ISP2-export out
 neighbor 172.20.127.253 remote-as 65015
 neighbor 172.20.127.253 next-hop-self
 neighbor 172.20.127.253 send-community extended
 neighbor 172.20.127.253 soft-reconfiguration inbound
ip prefix-list bgp-ALL seq 10 permit 0.0.0.0/0 le 32
ip prefix-list bgp-Advertise-ISP2 seq 10 permit 172.20.120.0/21 le 24
ip prefix-list bgp-Advertise-ISP2 seq 15 permit 192.168.30.15/32
ip prefix-list bgp-Advertise-ISP2 seq 20 permit 192.168.40.15/32
route-map bgp-ISP2-import permit 10
 match ip address prefix-list bgp-ALL
 set local-preference 100
route-map bgp-ISP2-export permit 10
 match ip address prefix-list bgp-Advertise-ISP2
route-map bgp-ISP2-export deny 20
 match ip address prefix-list bgp-ALL
snmp-server enable traps bgp

New Member

 Here's the BGP config of the

BGP configs

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