ifAlias SNMP MIB doesn't seem to work correctly on switches running 15.2E

[AURELIEN MERE]

Hello,

From 12.2 to 15.0(2)SE on catalyst switches, setting the ifAlias object in SNMP changes the "description" field in the configuration file, allowing it to be saved in case of a reboot.

It seems that this no longer works the same in 15.2(E). Setting the ifAlias correctly changes the name field when doing a "show interfaces status" but the description field in the configuration file is no longer modified, leading in information loss on reboot, even if a "wr" is issued before.

I can't find any information on this behavior change in the release notes or in the configuration guide. Can you tell me if it is a normal behavior now or if i'm doing something wrong and missing a command or something ?

I have the same standard SNMP v2c configuration in all switches, and i can reproduce the problem on 2960-S, 2960-X, 2960-C, 3560-X, 3750-X switches running 15.2(2)E3, 15.2(3)E3 or 15.2(4)E just by issuing a "snmpset -v1 -c $community $ip ifAlias.$ifnumber s 'myalias'"

Thanks for your help.

Aurélien

[charles.bueche]

Hi,

I do have the same problem on a stack of 3 WS-C3850-48P running 03.06.03E, after setting the ifAlias value by SNMP.

First, the status after SNMP set, shows what I want ("s=a,t=AP Cisco"):

device#show interfaces description | inc Gi1/0/12
Gi1/0/12 up up s=a,t=AP Cisco

snmpwalk -v 2c -c stuff device 1.3.6.1.2.1.31.1.1.1.18.14
iso.3.6.1.2.1.31.1.1.1.18.14 = STRING: "s=a,t=AP Cisco"

But why do show running still show the old value ?

device#show run interface Gi1/0/12
Building configuration...

Current configuration : 306 bytes
!
interface GigabitEthernet1/0/12
  description Access Point
  switchport access vlan 1132
  switchport mode access
  ip arp inspection trust
  ip arp inspection limit rate 256 burst interval 2
  no snmp trap link-status
  macro description AP | AP
  spanning-tree guard root
  ip dhcp snooping limit rate 100
end

Help welcome!!!

Charles

EDIT : similar issue on https://tools.cisco.com/bugsearch/bug/CSCuu83648

[gwendoline07]

Hi Charles,

I am facing the same issue.Configuring port description through a GUI platform and it does not show up in the show running config but is present under show interface description. Is there a command to fix this or does one need to update the IOS? Am currently running cat4500e-universalk9.SPA.03.07.00.E.152-3.E.bin. It's a Cisco 4510R+E.

Thanks.

[Palani Mohan]

You are running 03.07.00.E/15.2(3)E.

CSCuu83648 is fixed in 03.07.03.E/15.2(3)E3. Please google for cat4500e-universalk9.SPA.03.07.03.E.152-3.E3. The result should take you direct to the home page.

As far as workarounds go, your option is to assign port to a VLAN manually through CLI via "switchport access vlan X" command. To verify the port has been assigned to the intended VLAN used the following commands:

show vlan
sho run all | b interface GigabitEthernet

Sincerely .... Palani

[gwendoline07]

Thanks Palani. I will upgrade to a more recent version. Based on my hardware ,I plan on upgrading to cat4500e-universal.SPA.03.07.00.E.152-3.E.bin(recommended).

Thanks again.

[Palani Mohan]

Hi Gwen

CSCuu83648 is fixed in 03.07.03.E/15.2(3)E3.You are presently running cat4500e-universal.SPA.03.07.00.E.152-3.E. To get the fix, you need to upgrade to cat4500e-universalk9.SPA.03.07.03.E.152-3.E3

Kind regards ... Palani

[gwendoline07]

Thanks Palani.Will upgrade and give you feedback later.

[gwendoline07]

Hello Aurelien,

I am facing the same issue.Configuring port description through a GUI platform and it does not show up in the show running config but is present under show interface description. Is there a command to fix this or does one need to update the IOS? Am currently running cat4500e-universalk9.SPA.03.07.00.E.152-3.E.bin. It's a Cisco 4510R+E.

Thanks.

[AURELIEN MERE]

Hello gwendoline07,

After testing, I no longer have the problem with 15.2(2)E4 or 15.2(4)E1, so an IOS upgrade should fix the problem.

I haven't tested the 15.2(5)E train yet.

Please tell me if you encounter the problem again after the upgrade, I will check on my production 4500-X if I have the problem too.

Thanks,

Aurélien

[gwendoline07]

Thanks Aurelien,

Will upgrade before the week runs out and will keep you updated.

Cheers.