Can't find what you need?


• Ask the Community
• Create a Case
Reset Search
 

 

Article

Intermittent VRRP transitions and Network Outages

« Go Back

Information

 
TitleIntermittent VRRP transitions and Network Outages
Symptoms
  • NMS reports communication loss on multiple VLANs
  • Intermittently both routers master simultaneously
  • Master receiving VRRP hello packets from backup
show logging buffer
  <165>Jun 12 11:53:30 1.1.1.1 VRRP[1]VRRP: Advertisement received by 198.51.100.254 on Interface vlan.0.144 sent by 198.51.100.253, VRID 1 ; Advertisement dropped because this router is configured as the address owner for VRID 1
  • Backup VRRP  Backup logging buffer shows vrrP transitions
show logging buffer 
<165>Jun 12 11:54:12 1.1.1.2 VRRP[2]VRRP Event: Interface vlan.0.144, VRID 1, SUPERIOR Advertisement received from 198.51.100.254 (Priority 255)
<165>Jun 12 11:54:12 1.1.1.2 VRRP[2]VRRP State Change(event receive packet superior): Interface vlan.0.144, VRID 1, change from <master> to <backup>
<165>Jun 12 11:54:12 1.1.1.2 VRRP[2]VRRP Event: Interface vlan.0.145, VRID 1, SUPERIOR Advertisement received from 198.51.100.254 (Priority 255)
<165>Jun 12 11:54:12 1.1.1.2 VRRP[2]VRRP State Change(event receive packet superior): Interface vlan.0.145, VRID 1, change from <master> to <backup>
  • No physical port errors in show rmon stats
  • Ports in data path have high Large amounts of flow control pause frames that increment before an event 
show flowcontrol

Port TX Admin TX Oper RX Admin RX Oper TX Pause Count RX Pause Count
------------ -------- -------- -------- -------- -------------- --------------

tg.1.9 enabled enabled enabled enabled 0 2950680

tg.1.13 enabled enabled enabled enabled 0 568537



(Output clipped)
 
  • Logging buffer of some Securestacks show ports in stall mode due to flow control

show logging buffer 
<161>Mar 25 14:18:48 198.51.100.169 TXQMONITO[309054840]: txq_monitor.c(518) 835 This is from manager 1 %% Interface ge.1.20 is enabled to ignore pause as sequential transmit failures reached ignore pause threshold
<161>Mar 26 17:08:14 198.51.100.169 TXQMONITO[309054840]: txq_monitor.c(507) 836 This is from manager 1 %% Tx queue for interface ge.1.20 is in stalled mode


 
Environment
  • S-Series
  • Securestack

 
Cause
Flow  control sending pause frames preventing VRRP hello packets semt by the master from being received by the backup 
Resolution
Disable flow control on the Securestacks
set flowcontrol disable  
Additional notes

Feedback

 

Was this article helpful?


   

Feedback

Please tell us how we can make this article more useful.

Characters Remaining: 255