Preview Tool

Cisco Bug: CSCsy89011 - CBS3110G Fails to ARP the internal blade server

Last Modified

Jan 23, 2017

Products (81)

  • Cisco Blade Switches for HP
  • Cisco Catalyst 3560E-12D-E Switch
  • Cisco ME 3400-24TS-A Switch
  • Cisco Catalyst 3560G-48PS Switch
  • Cisco Catalyst 3560E-24TD-S Switch
  • Cisco Catalyst 3560E-48PD-E Switch
  • Cisco Catalyst 3750G-12S Switch
  • Cisco Catalyst 3560-12PC-S Compact Switch
  • Cisco Catalyst 2960G-24TC-L Switch
  • Cisco Catalyst 3560E-48PD-SF Switch
View all products in Bug Search Tool Login Required

Known Affected Releases

12.2(46)SE 12.2(50)SE

Description (partial)


Communication between the blade switch and blade server breaks after upgrading the switch from 12.2(40)EX2 to 12.2(46)SE. 

1. mac-address-table on the switch does not show the internal host MAC.
2. When we ping the internal host IP from the switch console, the ping fails leaving temporary ARP entry for the IP with incomplete mac-address.


The problem observed when the blade switch code is upgraded from 12.2(40)EX2 to 12.2(46)SE. Same observed on 12.2(50)SE too.

Following are the steps to re-create.

1.Enable native vlan tagging by 'vlan dot1q tag native'
2.Configure a vlan on blade switch.
3.Assign IP to the vlan interface. 
4. Identify a internal interface that connects to a blade server.
5. Assign the vlan to the interface.
6. Assign IP to the server in same IP subnet.

The switch and server can not establish bi-directional communication.  When ping is initiated on the switch to the server, the TCP dump initiated on the server indicates the ARP requests come from the switch to server and the server responds with ARP reply. But the switch does not receive, hence can not complete the ARP process and hence ping too fails.

Statically adding mac-address-table entry and ARP entry too did not help.
Bug details contain sensitive information and therefore require a account to be viewed.

Bug Details Include

  • Full Description (including symptoms, conditions and workarounds)
  • Status
  • Severity
  • Known Fixed Releases
  • Related Community Discussions
  • Number of Related Support Cases
Bug information is viewable for customers and partners who have a service contract. Registered users can view up to 200 bugs per month without a service contract.