In my lab I have several routers connected to each other via ospf, on that I have enabled MPLS and created at VPLS tunnel between two routers.
The VPLS tunnel is up and running.
In one end of the routers (A) where the tunnel is connected I have created a bridge witch include the vpls interface, on that bridge I have assigned the pppoe server.
On the other end of the VPLS tunnel (router E) I have created a new bridge, included the vpls interface and a ethernet interface, where Iam attaching a sixth router (F) who should act as a pppoe client. But when iam running a pppoe scan, the pppoe server dont show up.
A ↔ B ↔ C ↔ D ↔ E ↔ F
from the pppoe server, router A, who only powers router B,C,D,E. And connects to router D.
/interface bridge
add l2mtu=1500 mtu=1508 name=bridge1
/interface ethernet
set 1 poe-priority=10
set 2 poe-priority=10
set 3 poe-priority=10
set 4 poe-priority=10
/interface vpls
add disabled=no l2mtu=1500 mac-address=02:DE:B1:D0:BD:5C name=vpls1 \
remote-peer=10.0.2.2 vpls-id=10:10
/ip hotspot user profile
set [ find default=yes ] idle-timeout=none keepalive-timeout=2m
/ip pool
add name=pppoe ranges=20.20.20.20-20.20.20.29
/ppp profile
add local-address=20.20.20.1 name=profile1 remote-address=pppoe
/routing ospf area
add area-id=1.2.3.4 name=area1
/interface bridge port
add bridge=bridge1 interface=vpls1
/interface pppoe-server server
add default-profile=profile1 disabled=no interface=bridge1 max-mru=1500 \
max-mtu=1500 service-name=Vaxeltjanst
/ip address
add address=10.0.5.1/30 interface=ether4
/ip dhcp-client
add default-route-distance=0 disabled=no interface=ether1
/mpls ldp
set enabled=yes lsr-id=10.0.5.1 transport-address=10.0.5.1
/mpls ldp interface
add interface=ether4
/ppp secret
add name=ppp1 password=1234 profile=profile1
/routing ospf network
add area=area1 network=10.0.5.0/30
from router E
[admin@MikroTik] > export com
# jan/02/1970 03:58:58 by RouterOS 5.20
# software id = 6CU1-X91Q
#
/interface bridge
add l2mtu=1500 name=bridge1
/interface vpls
add disabled=no l2mtu=1500 mac-address=02:6A:70:10:E0:FA name=vpls1 remote-peer=10.0.5.1 vpls-id=\
10:10
/ip hotspot user profile
set [ find default=yes ] idle-timeout=none keepalive-timeout=2m
/routing ospf area
add area-id=1.2.3.4 name=area1
/interface bridge port
add bridge=bridge1 interface=vpls1
add bridge=bridge1 interface=ether3
/ip address
add address=10.0.2.2/30 interface=ether5
/ip neighbor discovery
set vpls1 disabled=yes
/mpls ldp
set enabled=yes lsr-id=10.0.2.2 transport-address=10.0.2.2
/mpls ldp interface
add interface=ether5
/routing ospf network
add area=area1 network=10.0.2.0/30
[admin@MikroTik] >
Check Your MTU settings trough Your setup. It will drop VPLS if packet get fragmented.
I have a rule:
Minimum 1600 l2mtu at all Interfaces (makes it possible to use old rb 532)
Then have a MPLS mtu set to 1590 to all interfaces. (just to "have some Space. Why is every one reaching limits all the time?)
Then let the VPLS Interface have l2mtu to 1525 ( or more if you want to run MPLS troug the tunnel) and mtu to 1510 (why not like earlier have some Space)
In this setup, you should not run into MTU troble.
I got it to work by creating a lobridge interface and set a unique ip on that. I thought it was enough whit a IP from one of the interfaces that was used.
Now my only question is to figure out the mtu settings. I changed to rb951 routers instead who had more l2mtu level than 750g routers.
But I tried on of the 750G router in my “chain” of routers and it worked whit my new config?
Yep. To have a full 1500 bytes frame With mpls, you have to use a routerboard that support higer l2mtu. 750GL will do the job. (but you should minimum use a 2011 due to performance)
but how come that it worked whit a rb750g who only supports l2mtu 1524?
why iam asking is that we are about to implement mpls vpls and pppoe over our wireless network where many devices are rb411ah and rb433 who only supports 1526 l2mtu. Do we have to change all of them to newer ones?
It dont work with full frames. Your pppoe clients will get a MTU error. ITs possible to fix, using mangle rules chaning MMS etc, but your performance will drop to 1/2. For one full frame, you will have to send 2 packets trough your network.
If your router get a 1500 byte package, and you put MPLS/VPLS to this. it will at once get 1536 bytes big.- When it reatch a interface not capable to forward a l2mtu of 1536, it wil just get dropped.
If the package com in to MPLS is smaller or less than 1500, its possible to get it trough your net. eg, a ICMP ping packet, standard 64 bytes.
well, then you have to have a change mss rule somehow, and you get about 1/2 the speed over Your links. You need to send 2 packages trough Your network, to get one frame passed. ( fragmention). The router also get more stressed.
pppoe should be 1492 to Ethernet and 1500 to wlan Interface if possible. And is all Your traffic pppoe? _how about managment?
My MPLS MTU on all interfacec throw network is 1524 (becouse Rb433GL :-/), VPLS MTU 1500 and when I ping with 1500 (router-router) there isn no fragmentation??
It is not clear to me, you said pppoe MTU 1492 on ethernet and 1500 to wlan? Can you explain…
..becouse 1492+8 can be one frame, and 1480+8 can be one frame to.