Getting % BGP malformed error

[jaisharma3377]

Hello Experts,

On one of my EBGP peering I am getting a %BGP-6-MALFORMEDATTR for every hour continuously .Can you let me know the reason for the same or how can I check.It is a vanilla eBGP peer with no special config.Will show ip bgp neighbor  x.x.x.x | begin last reset heal and putting the o/p on the BGP dump decode ?

This is the error msg

%BGP-6-MALFORMEDATTR: Malformed attribute in (BGP(0) Prefixes:y.y.y.y ) received from x.x.x.x

Oct  3 2019 11:14:56.523: %BGP-6-MSGDUMP_LIMIT: unsupported or mal-formatted message received from x.x.x.x: 

Thanks & Regards

Jai Sharma

[Georg Pauwen]

Hello,

could be a bug such as the one below. Which IOS version are you running ?

XE3.13 rejects routes from ebgp peer due to malformed ATTR-SET attribute
CSCus01544
Description
Symptom:
The bgp routes are rejected and the following logs is displayed when ATTR_SET is sent over eBGP peering
*Nov 26 12:46:14.462: %BGP-6-MSGDUMP_LIMIT: unsupported or mal-formatted message received from 10.0.6.1:
FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFF 007F 0200 0000 6840 0101 0040 020E 0203
0000 0FA4 0000 3637 0000 0FA4 C010 0800 020F A400 0377 E5E0 8020 0000 0FA4 4001
0100 4002 0040 0504 0000 0078 C008 0428 2BEA 6180 0A04 0000 0003 900E 0021 0001
800C 0000 0000 0000 0000 0A00 0601 0078 5B4D C100 000F A400 0377 E601 0000 04
*Nov 26 12:46:14.463: %BGP-6-MALFORMEDATTR: Malformed attribute in (BGP(4) Prefixes: 4004:227302:1.0.0.4/32 ) received from 10.0.6.1,
*Nov 26 12:56:15.577: %BGP-6-MSGDUMP_LIMIT: unsupported or mal-formatted message received from 10.0.6.1:

Conditions:
The bgp routes are rejected and the following logs is displayed when ATTR_SET is sent over eBGP peering

Workaround:
No workaround

[jaisharma3377]

Hi Georg,

Thanks for the reply. I will get back with the version soon.

Thanks & Regards

Jai Sharma

[jaisharma3377]

Hi,

Below is the system image.It seems this was coming due to due to AS path empty in the update message.

System image file is "bootflash:asr1000-universalk9.16.04.01.SPA.bin

[00utk43t7wMR1OMpb5d6]

Did you solve it?

[Georg Pauwen]

Hello,

you have the exact same error ? On which platform/IOS version ?

[00utk43t7wMR1OMpb5d6]

I kinda have the same one not at all I get the

Jul 16 17:39:58.033: %BGP-6-MALFORMEDATTR: Malformed attribute in (BGP(0)
Prefixes: I haven’t been able to fix it or at least figure out what is going
on

I am running IOS XE 16.07.01

Any thoughts would be helpful

thanks

[Georg Pauwen]

Hello,

what does your BGP configuration (and BGP topology table) look like ? What is your BGP peer sending you ?