ME3800 DHCP relay packets problem with.

kzryumov1 · ‎03-29-2012

Hi everyone,

I faced with issue on ME3800.

interface Vlan77

description ### Staging LRS ###

ip dhcp relay information trusted

ip address 10.186.71.1 255.255.255.0 secondary

ip address 10.127.254.1 255.255.255.0

ip helper-address 82.199.96.130

no ip redirects

no ip unreachables

no ip proxy-arp

ip pim sparse-mode

With that configuration there is no problem with DHCP Relay packets.

But if I add on interface #xconnect 82.199.119.1 77 encapsulation mpls it will stop forward DHCP relay packets immediately. All other traffic transfers without problem.

Cisco IOS Software, ME380x Software (ME380x-UNIVERSAL-M), Version 15.1(2)EY1a

Who can explain where is the cause of issue?

Thanks.

kzryumov1 · ‎04-02-2012

If anyone have this problem too I can help.

There is a bug.

CSCtx76780 Bug Details

DHCP relay not working on ME3600 when using xconnect under VLAN int

Symptoms: DHCP relay does not work on Cisco ME3600.

Conditions: This issue is observed if you configure at the same time a "ip
helper-address" and an xconnect under the VLAN interface. It is observed on
ME3600/ME3800 platforms running Cisco IOS Release 15.1(2)EY1 or earlier.

Workaround: There is no workaround.

1st Found-In http://tools.cisco.com/Support/BugToolKit/images/Field%20Definitions.html
15.1(2)EY1a

Fixed-In http://tools.cisco.com/Support/BugToolKit/images/Field%20Definitions.html
15.2(1.18)S0.14
15.2(2.13)S
15.1(2)EY2

It was added on cisco.com bug toolkit recently ))).

cdemont · ‎01-11-2013

Hello,

I also would like to point out a bug on ME3600 with ip helper.

I'm running IOS 15.2(2)S2 and all PCs behind the ME3600 passing through ip helper address to get an IP from a central DHCP server, when doing ipconfig /all on the PCs, the DHCP server address is set to the VLAN interface of the ME3600, not the DHCP server !

I've never seen that before.

All other PCs behind other L3 swithes (C3650, C3750 etc..) are showing the right IP address of the DHCP server.

Have you any feedback about a such bug ??

Regards,

Christophe