Got it
Huawei Enterprise Support Community
Community Forums Routing & Switching
BGP PMTUD on Huawei NE ?

BGP PMTUD on Huawei NE ?

Latest reply: Dec 28, 2017 11:33:16 2307 3 0 0 0
display all floors 1#
Hi guys,


Does anyone test the BGP PMTUD on Huawei NE20 and NE40 on iBGP peers? The Huawei behaviour is different than Cisco, especially on v8.120 on NE20.

* When BGP PMTUD is disabled on both peers, BGP MSS is still 8960 (when all interface MTUS are 9000). If discovery is disabled, an interface MTU on the path can be default (as 1500) so this shouldnt be 8960 as my understanding on RFC.

* When BGP PMTUD is enabled and some interface MTUs on path are changed to 6000; 
**  the v8.120 shows MSS as 1460 (which is not OK), 
**  the v5.160 shows MSS as 5960 (which is OK).

Huawei NE20E        Version 8.120 (NE20E V800R008C10SPC300)

Huawei NE40E        Version 5.160 (NE40E&80E V600R008C10SPC300)


Not: Also icmp protocol 1 is permittedon all devices.

Is there any difference on default config between the peers? Or what is the Huawei behaviour on BGP PMTUD?

Thanks,

  • x
  • convention：

Like (0) Dislike (0) Favorite(0) Share Report
Previous: how to reboot the switch s5700 using snmp
Next: help to Bootrom password recovery for Switch Quidway S3352P-SI
gululu
Created Dec 12, 2017 05:54:52

please wait for help！
View more
  • x
  • convention：
MRYang
Created Dec 18, 2017 06:20:58

1、MTU=MSS+TCP Header+IP Header
2、Default config of PMTU is the same
View more
  • x
  • convention：
ferdibulbul
Created Dec 28, 2017 11:33:16

I know what is BGP PMTUD and how it works on other vendors. For ex, Huawei behavior is not same as Cisco. On Cisco; When BGP PMTUD is disabled, the minimum BGP MSS is 536 bytes. When BGP PMTUD is enabled, BGP MSS is "pathmtu-TCPheader-IPheader".

I opened a case to Huawei and I couldnt get a proper answer that what the Huawei behavior is on BGP PMTUD. I did multiple tests, but even the PMTUD is disabled, BGP MSS is 8960 on most neighbors (far end neigbors and interface MTU is 9000). If PMTUD is disabled, router should use a default minimum MSS value for this not the physical interface MTU parameter to calculate MSS.

My question is if anyone did some tests about BGP PMTUD feature, also Huawei NE behaviour?

Thanks
View more
  • x
  • convention：
Back to list

Comment

Advanced
B Color Image Link Quote Code Smilies
You need to log in to comment to the post Login | Register
Comment

Notice: To protect the legitimate rights and interests of you, the community, and third parties, do not release content that may bring legal risks to all parties, including but are not limited to the following:
  • Politically sensitive content
  • Content concerning pornography, gambling, and drug abuse
  • Content that may disclose or infringe upon others ' commercial secrets, intellectual properties, including trade marks, copyrights, and patents, and personal privacy
Do not share your account and password with others. All operations performed using your account will be regarded as your own actions and all consequences arising therefrom will be borne by you. For details, see " User Agreement."

My Followers

Login and enjoy all the member benefits

Login
Huawei Website Support About Huawei Privacy User Agreement Terms of Use Cookies Cookie Settings
Huawei Enterprise Huawei Carrier Forum Training & Certification

Contact Us: e_online@huawei.com Copyright © 2022 Huawei Technologies Co., Ltd. All rights reserved.

APP

Block
Are you sure to block this user?
Users on your blacklist cannot comment on your post,cannot mention you, cannot send you private messages.
Reminder
Please bind your phone number to obtain invitation bonus.
Information Protection Guide
Thanks for using Huawei Enterprise Support Community! We will help you learn how we collect, use, store and share your personal information and the rights you have in accordance with Privacy Policy and User Agreement.