Preview Tool

Cisco Bug: CSCvi52166 - ASR does not understand untagged CDP packets in native vlan

Last Modified

Jun 18, 2018

Products (1)

  • Cisco IOS

Known Affected Releases

16.6.4 Everest-16.6.1

Description (partial)

After upgrade 3k switch from 3.6/3.7 to 16.3 if ASR connected to this switch and trunk is configured, ASR can stop see 3 switch in CDP neighbors.

Reason is

with the following config on 3k switch

interface TenGigabitEthernet3/1/3
 switchport trunk native vlan 10
 switchport mode trunk
 switchport nonegotiate
 ip arp inspection trust
 ip dhcp snooping trust

switch sends CDP packets
1. 3.6 - tagged
2. 16.3.5b untagged
3. 16.6.2 tagged

trunk between ASR and 3k switch
3k switch on 16.3
no native vlan in trunk list on ASR or no ""vlan dot1q tag native" 3850/3650
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.