vrid peering

[ct_yau]

The following sample configuration is provided in http://www.cisco.com/univercd/cc/td/doc/product/webscale/css/css_730/redundgd/vipredun.htm#wp1109382 :

!************************** CIRCUIT **************************

circuit VLAN1

ip address 192.168.100.5 255.255.255.0

ip virtual-router 1 priority 101 preempt

ip critical-reporter 1 r1

circuit VLAN2

ip address 172.16.27.12 255.255.255.0

ip virtual-router 2 priority 101 preempt

ip critical-reporter 2 r1

!************************** REPORTER **************************

reporter r1

type vrid-peering

vrid 192.168.100.5 1

vrid 172.16.27.12 2

active

I cannot understand the benefit of the reporter. Here is a scenario:

Time n :-

CSS1: VIP(Master) v-int(Master) reporter (Master)

CSS2: VIP(Backup) v-int(Backup) reporter (Backup)

Time n+1: -

Suppose there is a link fail on VIP interface of CSS1.

CSS1: VIP(Down) v-int(Master) reporter (Down)

CSS2: VIP(Stay Backup because reporter state is Backup) v-int(Backup, same reason) reporter (Backup)

Time n+2 :-

CSS1: VIP(Down) v-int(Down because reporter is Down) reporter (Down)

CSS2: VIP(Backup) v-int(Backup) reporter (Backup)

Neither CSS1 nor CSS2 become Master!

Is the VIRD peering supposed to be configured only on the primary CSS? Also, CSS1 will never be primary again even when the link is back up. What to do if I want CSS1 be primary when links become normal? Am I misunderstanging anthing?

[Gilles Dufour]

Actually there are 2 states.

Independent state and dependent state.

In other words, a state that reflects the state of the VR if there was no reporter and a state with the reporter.

So, when the master goes down, the backup independents state will switch from back to master.

At time n+2 the independent state is down/down on CSS1 and Master/Master on CSS2, so the reporter state will also move to Master on CSS2.

Gilles.