EoMPLS/VPLS ....!!!!

RouterOS Forwarding Protocols
1

Hi…

I would like to share my problem with expert people

I install MPLS/VPLS Between two RB1100AHx2 routers using ether1 at both ends.. (R1 , R2)

I add vpls and config MPLS very simple and both vpls are up and running..

I bridge vpls interface with ether13 at both router to have transparent bridge…!!!

Now when I ping 10.1.1.1 IP for R3 from my laptop I have reply with 0 ms …

My problem that can do any data transfer…???

Could any one tell me where is my problem..

I relies its some where in MTU adjustment …

I change MPLS-MTU=1526 to support the maximum possible of headers..! But no this is solve..!!

Hope fully I can have reply to solve my connection..!!!

For more info please see attached Diag!!

Thanks

Ali
EoMPSL-VPLS.jpg

2

Check and make sure ALL interfaces between the routers have an MTU of 1526

This means ether1 on each router. Also if you are passing vlan tagged packets make sure your pw-type is set to tagged ethernet.

The LAN side interfaces can stay on default 1500.

I hope this helps!
EoMPSL-VPLS.jpg

3

Hi..

Thanks for reply

I would like to inform you that already I did but no thing solve..

Today I start reduce changing the vpls MTU till reach 1470 its running but didnt get full speed..

Look like fragmentation is overloading and max get only 8mpb from 50megs..

I wonder if I change the interface MTU for ether1 from 1500 to 1526 or 1530 so he can handel the extra 26 or 30 byte more in the frame header. without need to change inside the vpls or mpls mtu ..interface..

I will do this test and will write the update..

Thanks

4

This is EXACTLY what you need to do, and is what I was trying to explain with my post.


Good luck :slight_smile:

5

MPLS labelled packets should not adhere to L3 MTU setting on the /interface. It should only adhere to /mpls/interface MTU.

6

Adjust the l2mtu parameter on the Ethernet port to something higher than 1500. The RB1100AHx2 supports a maximum l2mtu of 9498.

/interface ethernet set ether1 l2mtu=9498
7

Hi Guys

I just return with Success result…

All what we that is change the MTU of VPLS from 1500 to 1504 ( as we do have Vlan in our network)

And change the MPLS-MTU=(from 1508) to 1500 / mpls interfaces

Now its working fine..

Pleas see attached result

Regards
Ali.
VPLS TESTING.jpg

8

Hi Guys
how and where you think the vlas with vpls? I have a p2p sxt with vpls http://wiki.mikrotik.com/wiki/Transparently_Bridge_two_Networks_using_MPLS According to the guide I pass vlans go through this link.
many Thanks
regards

9

Sten is correct. Interface MTU is irrelevant when the packet egressing is an MPLS labelled packet.
I usually make the MTU the same as my MPLS mtu purely to make fault finding easier e.g. If 1530 byte packet with DF bit set will traverse the path than 1530byte MPLS packet should, if it wont pass then i usually check L2 MTU on the path and make sure it is large enough.

10

Hello Experts,

I have similar issue, my MPLS MTU is 1550, Ethernet MTU actual 1500, L2MTU 1598, VPLS are 1508 advertised, and running at 1500, and i can only pass 1500,

Do i need to change, ethernet MTU to higher? Actual MTU
on VPLS, do i also change the actual MTU ? as i advertise 1520

Many thanks for your time.

11

nice trick: ))) .but you know if you calculate on proper way…you will never get issues

12

If only Mikrotik supported MPLS LSP ping :slight_smile:

13

Hello,

Can you please help on below:

I have similar issue, my MPLS MTU is 1550, Ethernet MTU actual 1500, L2MTU 1598, VPLS are 1508 advertised, and running at 1500, and i can only pass 1500,

Do i need to change, ethernet MTU to higher? Actual MTU
on VPLS, do i also change the actual MTU ? as i advertise 1520