Speed port plus routing performance problem and static route issue

[jveekeres]

Hi Guru's

As I'm Dutch I'm posting in English but feel free to reply in Greek (I can read it fine but writing as another thing).
I'm a professional Audiovisual and IT tech with experience in layer 3 switches and router setups.

I'm having the following issue and several colleagues and I are pulling our hairs out. (not many left in my case).

Ote is including the Sercom VDSL 100Mb speedportplus routers. With several of the routers we see the following:

1. In static routes you can only enter ranges. The network mask 255.255.255.255 is not allowed. That makes it impossible to make static routes to single IP's. With the previous OTE routers from ZTE this was not the case. Not a very big problem but still, it is a bug.

2. And this is the one I need help with. When connecting these Sercom routers to a layer3 switch (sometime replacing a ZTE that has been working fine for years) with multiple VLAN's, downloads fail after a few seconds on all routed clients. On clients that are in the same VLAN as the router downloads work fine. Putting the old OTE ZTE router back restores download ability.

So, let's say OTE router has its default 192.168.1.1 and connects to a layer 3 port on a cisco switch on 192.168.1.254. Other VLAN's on the Cisco switch are 192.168.2.x and 192.168.3.x. Sercom router has 2 static routes added:

192.168.2.0 - 255.255.255.0 - 192.168.1.254
192.168.3.0 - 255.255.255.0 - 192.168.1.254

Internet access looks fine on all pc's in all 3 vlan's. You can browse web pages, watch movies on youtube, use ftp, anydesk, teamviewer etc.. however downloading large files only works in 192.168.1.0. On the other 2 VLAN's they fail after a few seconds. You see the initial download start and then quickly the speed drops and drops and ends up to zero. It's as if the router can't handle the traffic over another router. We have been looking into flow control, MTU, switching ports on the cisco switch back to 100Mbps but nothing seems to help. Again when putting back the the previous OTE ZTE router with the same config all is fine in all VLAN's. Only the DSL speed is lower. Routers have latest OTE5 firmware

Has anybody ever seen this behavior? Are these Sercom routers simply buggy and need to be replaced or are there (hidden) settings that need to be adjusted?

Thanks for any help.

Jeroen

[jveekeres]

Now things become interesting.

This morning I learned that another setup which was having the same problem was able to resolve the issue with a router restart yesterday.
I had performed several restarts last week to no avail, but tried again this afternoon after facing the same issue this morning.

And indeed. This afternoon's restart has fixed the issue!!!. Ote must have discovered something and resolved the issue on their side.
Would be nice to see that confirmed from OTE's side but I guess it will never happen.

Jeroen