Last months we are getting clients comments about erratic and random disconnects, movie freezing, pages partially loading.
But only only on clients that are PPPoE client 3rd party Wifi router. (So these 3rd party wifi router do the client auth. and are src-natting client traffic into our network and the internet.
Most clients have PPPoE client on the Mikrotik CPE.
Only clients with 3rd party CPE (Mimosa, eCambium or 60Ghz wAP clients) have PPPoE-client on 3rd party router (TP-link, Mimosa, Netis, etc.)
In the PPPoE server all Mikrotik clients are showing MTU of 1500 while all clients that authenticate with 3rd party devices show 1480 or 1492 as their 'actual MTU'
The comments and complaints come from (some) of these clients having 3rd party PPPoE-clients running.
So I dove into the MTU settings documentation online and on this forum but like always, too much info and now I'm lost in the forest....
All our gateway routers as well backhauls are basically Mikrotik gear.
PPPoE server setting (CCR1036 internet gateway router):
dd address-list="" !bridge !bridge-horizon !bridge-path-cost !bridge-port-priority change-tcp-mss=yes dns-server=10.10.10.2 !idle-timeout !incoming-filter !insert-queue-before \
!interface-list local-address=192.168.200.1 name=defaultMTU1500noTCP_MSS on-down="" on-up="" only-one=default !outgoing-filter !parent-queue !queue-type !rate-limit !remote-address \
!session-timeout use-compression=default use-encryption=default use-mpls=default use-upnp=default !wins-server
/interface pppoe-server server
add authentication=pap,chap,mschap1,mschap2 default-profile=defaultMTU1500noTCP_MSS disabled=no interface=Bridge_PPPoE keepalive-timeout=30 max-mru=1500 max-mtu=1500 max-sessio
mrru=disabled one-session-per-host=yes pado-delay=0 service-name=internet
Mikrotik CPE typical:
add add-default-route=yes disabled=no interface=wlan1 keepalive-timeout=60 max-mru=1500 max-mtu=1500 name=pppoe-out1 \
service-name=internet use-peer-dns=yes user="Clientname+number"
#### so here we have both server and client working with mtu = 1500####
3rd party typical:
depending on the brand the Wifi router that is performing PPPoE auth has a mtu set of 1492 or 1498
###So here package leaving this router toward internet over our network, or towards client LAN are never bigger then this?#####
(Actually 99% of Mikrotik CPE clients that have PPPoE performed in the CPE also have 3rd party wifi router behind the CPE for the LAN. Again with 1492 or 1498 mtu. But no more PPPoE of course)
Connection between border gateway and client PPPoE device runs over wired and wireless MPLS network, in some parts Vlan's and off course some clients use VPN
What would be best advice for setting?
Need to set border gateway PPPoE server to lower mtu to allow fragmentation or disregard to take place in the border router for package from remote host destination client?
Or should I better work with two PPPoE server profiles. One service for Mikrotik devices, and one for 3rd party devices? Now I can set the optimum (or even bigger?) for Mikrotik network and smaller mtu for 3rd party?
Could somebody give me a 'mtu and PPPoE server for dummies' explanation so I can enhance the performance of our network and silence the complaints from some clients....?