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buset1974
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VPLS MTU problem on V7 (7.9beta4)

Tue Mar 28, 2023 8:34 am

Hi,

On well run ospf +mpls network ,vpls created cannot reached MTU more than 1490.

Problem happen if one or both of the PE using v7

but if both PE using v6 everything running well.

[admin@SIDE-2] > ping 192.168.200.5 size=1490 do-not-fragment
SEQ HOST SIZE TTL TIME STATUS
0 192.168.200.5 1490 64 3ms
1 192.168.200.5 1490 64 2ms
sent=2 received=2 packet-loss=0% min-rtt=2ms avg-rtt=2ms max-rtt=3ms

[admin@SIDE-2] > ping 192.168.200.5 size=1491 do-not-fragment
SEQ HOST SIZE TTL TIME STATUS
0 192.168.200.5 timeout
1 192.168.200.5 timeout
sent=2 received=0 packet-loss=100%

here is the topology & the rsc file from both PE.
vpls-problem.jpg
thx
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psannz
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Re: VPLS MTU problem on V7 (7.9beta4)

Tue Mar 28, 2023 9:27 am

Check line 50 in the PE-5-V7.rsc
Are you certain, you want that disabled?
 
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nichky
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Re: VPLS MTU problem on V7 (7.9beta4)

Tue Mar 28, 2023 10:32 am

Did u try 7.8?
 
buset1974
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Re: VPLS MTU problem on V7 (7.9beta4)

Thu Mar 30, 2023 5:30 pm

Check line 50 in the PE-5-V7.rsc
Are you certain, you want that disabled?
i tried to enable disable that line, result is the same.
 
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StubArea51
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Re: VPLS MTU problem on V7 (7.9beta4)

Thu Mar 30, 2023 6:09 pm

I've been able to use 1500 bytes with ROSv7 and VPLS for quite a while with no issues. It' actually how my home network is built which has been running VPLS on ROSv7 for more than a year. We've also got some ISP clients using it in prod.

What hardware is this running on? The image looks like GNS3/CHR

Also, if you're exceeding the size, you should get this message and not a timeout.
[adminhome@rtr-ap-2.kit.myersfam.net] > ping 8.8.8.8 do-not-fragment size=1501
  SEQ HOST                                     SIZE TTL TIME       STATUS                                              
    0                                                              packet too large and cannot be fragmented           
    1                                                              packet too large and cannot be fragmented           
    2                                                              packet too large and cannot be fragmented           
    3                                                              packet too large and cannot be fragmented           
    4                                                              packet too large and cannot be fragmented           
 
buset1974
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Re: VPLS MTU problem on V7 (7.9beta4)

Sat Apr 01, 2023 8:39 am

I've been able to use 1500 bytes with ROSv7 and VPLS for quite a while with no issues. It' actually how my home network is built which has been running VPLS on ROSv7 for more than a year. We've also got some ISP clients using it in prod.

What hardware is this running on? The image looks like GNS3/CHR

Also, if you're exceeding the size, you should get this message and not a timeout.
[adminhome@rtr-ap-2.kit.myersfam.net] > ping 8.8.8.8 do-not-fragment size=1501
  SEQ HOST                                     SIZE TTL TIME       STATUS                                              
    0                                                              packet too large and cannot be fragmented           
    1                                                              packet too large and cannot be fragmented           
    2                                                              packet too large and cannot be fragmented           
    3                                                              packet too large and cannot be fragmented           
    4                                                              packet too large and cannot be fragmented           
Yes problem happen in gns3/chr labs.
In real production i just find out it works for 1500 mtu.
And also in real production, i find out that vpls with jumbo frame mtu were problem, for example vpls for mtu 3000 maximum mtu reached is 1540
Can u try create vpls with mtu bigger than 1540 with v7?

Thx
 
BabbyTarnama
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Re: VPLS MTU problem on V7 (7.9beta4)

Mon Apr 03, 2023 10:59 am

Based on the information provided, it seems that the issue with the VPLS MTU size is related to the version of PE being used. If both PE are using v6, everything runs smoothly, but if one or both of them are using v7, the VPLS cannot reach MTU more than 1490.

This could be due to a compatibility issue between the different versions of PE. It's possible that v7 has a different way of handling VPLS MTU sizes, which could result in the issue that you are facing.

To resolve this issue, you may need to consider upgrading the PE to a version that is compatible with VPLS MTU sizes greater than 1490. Alternatively, you could try adjusting the MTU settings on the PE to ensure that they are configured correctly for the VPLS network.

I would suggest consulting with your network provider or an expert in the field to get a more detailed analysis of the issue and to explore potential solutions to resolve it.
 
buset1974
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Re: VPLS MTU problem on V7 (7.9beta4)

Thu Aug 31, 2023 8:19 am

hi,

i tried both PE's (PE2 & PE5) using v.7.11
and the result still the same , i cannot create vpls greater than 1558

Is it a bugs? I did change PW-control word into "default" or "Enabled" both did not works

thx
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sup5
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Re: VPLS MTU problem on V7 (7.9beta4)

Thu Aug 31, 2023 10:00 am

Has someone considered this bug?
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