09-02-2009 04:45 PM - edited 03-06-2019 07:33 AM
HSRP behaviour
Hi experts! I have an HSRP configuration between PC-Linux and 2 routers, and this is the configuration:
ROUTER-1
interface Vlan10
ip address 200.25.192.18 255.255.255.224
standby 110 ip 200.25.192.17
standby 110 timers msec 300 1
standby 110 preempt
ROUTER-2
interface Vlan10
ip address 200.25.192.19 255.255.255.224
standby 110 ip 200.25.192.17
standby 110 timers msec 300 1
standby 110 priority 200
standby 110 preempt
Hi experts! I have an HSRP configuration between PC-Linux and 2 routers, and this is the configuration:
ROUTER-1
interface Vlan10
ip address 200.25.192.18 255.255.255.224
standby 110 ip 200.25.192.17
standby 110 timers msec 300 1
standby 110 preempt
ROUTER-2
interface Vlan10
ip address 200.25.192.19 255.255.255.224
standby 110 ip 200.25.192.17
standby 110 timers msec 300 1
standby 110 priority 200
standby 110 preempt
So, ROUTER-2 is "active" and ROUTER-1 is "standby". Also, I have a Port Channel between these 2 routers. In normal conditions everything is working fine:
- ROUTER1 is power-on, ROUTER2 link is power-on, the traffic is going through ROUTER2.
- ROUTER1 is power-OFF, ROUTER2 is power-on, the traffic is going through ROUTER2.
- ROUTER1 is power-on, ROUTER2 is power-OFF, the traffic is going through ROUTER1.
But I am not sure about the behaviour when the router is power-on but it has a 100% of CPU Process. Normally, the HSRP is verifying the interfaces and when the process is high the interfaces are still up. I have some doubts about HSRP:
1.- When ROUTER2 (active) is with 100% CPU Process, does the traffic must siwtch to ROUTER1?
2.- Does PC-Linux know if ROUTER2 is totally down even when it has 100% CPU Process?
3.- Does HSRP work if the router is power-off of it has a 100% process?
Thanks guys!
Saludos,
Carlos*
09-02-2009 04:56 PM
1. The answer is it depends. If ROUTER2 loses its heartbeat (HSRP HELLO) with ROUTER1 due to high CPU, then ROUTER1 will take over. If heartbeat still present, then ROUTER1 will not take over.
2. PC-Linux will not know ROUTER2 is down or not. Since HSRP uses virtual MAC address, and when ROUTER1 takes over, it will take over the virtual MAC also.
3. Do not understand your question.
HTH,
jerry
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