Clicksilver Ethenet Modem MTU Problem

Ro-76

Hi,

I've got the Zyxel Prestige 645R-A1 with my clicksilver account (paid 30euro extra for ethernet version).

I was having all the MTU issues discussed elsewhere, and did the MTU test, and found my optimum MTU was 1300, so I changed the MTU of my NIC to 1300 with DrTCP. That helped a lot, but I am now increasingly getting the same problems of site inaccessibility, which is remedied by using the proxy.

I contacted UTV support, who told me that I needed to change the MTU on the modem, and that the DrTCP option would not work for ethernet modem users. unfortunately, UTV were unable to tell me how to change the MTU. It's not possible through the web interface, and using the telbet interface, I can access the modem, and even edit the autoexec.net file in the firmware, but I cannot find a command that will change the MTU. (the default setting on the modem is 1492)

Has anyone else has a similar problem, or found a solution?

Thanks,

Ronan

dub45

The wonders of google! the link is Zyxel support

Category >> Router General Keyword
Search within these results

Change MTU size in the Prestige router
Q: How do I change the MTU size in the Prestige router?

A: MTU stands for maximum transmission unit. The default MTU is 1500, but you
can change it by using the following CI commands. To keep the commands in
memory in every reboot, please enter it in autoexec.net file.

The procedure is as follows.

1. List all iface by `ip ifconfig`. You will get all the iface configuration
about the IP network.
2. Enter `sys edit autoexec.net` and insert the following command.
3. If you want to set a iface to other MTU value, say enif0, use

ip ifconfig enif0 < ipaddr >/< mask bit > mtu < size >

4. Save the above command.
5. Use `ip ifconfig` again to see if it`s changed.

Although the Prestige allows you to change the MTU, however, we suggest you leave the value default (i.e., 1500) because it is the
most case. If you thrink the value, many packets will have overhead
because of fagmentation and thus other routers on the way may not
receive it correctly.

Ro-76

Originally posted by dub45
The wonders of google! the link is Zyxel support

Category >> Router General Keyword
Search within these results

Change MTU size in the Prestige router
Q: How do I change the MTU size in the Prestige router?

A: MTU stands for maximum transmission unit. The default MTU is 1500, but you
can change it by using the following CI commands. To keep the commands in
memory in every reboot, please enter it in autoexec.net file.

The procedure is as follows.

1. List all iface by `ip ifconfig`. You will get all the iface configuration
about the IP network.
2. Enter `sys edit autoexec.net` and insert the following command.
3. If you want to set a iface to other MTU value, say enif0, use

ip ifconfig enif0 < ipaddr >/< mask bit > mtu < size >

4. Save the above command.
5. Use `ip ifconfig` again to see if it`s changed.

Although the Prestige allows you to change the MTU, however, we suggest you leave the value default (i.e., 1500) because it is the
most case. If you thrink the value, many packets will have overhead
because of fagmentation and thus other routers on the way may not
receive it correctly.

I did try the Google route, and did find the same info. The problem is that I, or UTV support do not know what to insert for "< ipaddr >/< mask bit >". It's a bit dissappointing, since UTV are responsible for supporting this router, and Zyxel do not support any products, unless bought directly from them.

Ro

Frank Grimes

Originally posted by Ro-76
I did try the Google route, and did find the same info. The problem is that I, or UTV support do not know what to insert for "< ipaddr >/< mask bit >". It's a bit dissappointing, since UTV are responsible for supporting this router, and Zyxel do not support any products, unless bought directly from them.

Ro

I would imagine it's the IP address and subnet mask of the router's ethernet interface.

dub45

Originally posted by Ro-76
I did try the Google route, and did find the same info. The problem is that I, or UTV support do not know what to insert for "< ipaddr >/< mask bit >". It's a bit dissappointing, since UTV are responsible for supporting this router, and Zyxel do not support any products, unless bought directly from them.

Ro

It might be worth posting to the UTV support group as some of the teccie minded people might be able to help you.

Ripwave

Originally posted by Ro-76
I did try the Google route, and did find the same info. The problem is that I, or UTV support do not know what to insert for "< ipaddr >/< mask bit >".

Yo're supposed to get that info from the ip ifconfig command that you do first.

Squall

Looks to me like you need to enter the IP address and subnet mask of you NIC card.

Ripwave

Originally posted by Squall
Looks to me like you need to enter the IP address and subnet mask of you NIC card.

He's trying to set the MTU on his router - the IP address of his NIC won't help.

Ro-76

Just got a call from a very helpful person at systemhouse support, who are responsible for ZyXel support in Ireland. He reckons that it may not be an MTU problem, and that all the MTU problems with UTV have been with USB modems.

Anyhow, he's going to go through altering the settings tomorrow with me, and we'll take it from there.

BTW, he says that the <ipaddr> is probably not needed and the <mask bit> is not the subnet mask, but some other number like 24. (Was driving at the time he called, so could not talk for long).

Ro

Couch Potato

Anybody know what the value of the MTU should be for routers - what have utv suggested the value should be ?

dub45

Originally posted by Couch Potato
Anybody know what the value of the MTU should be for routers - what have utv suggested the value should be ?

UTV suggest 1492 but there were variances on this around the time there were having lots of problems a while back. There is some stuff in the UTV support group about this around the 30th March if you want to have alook.

mancman

Originally posted by Ro-76
Just got a call from a very helpful person at systemhouse support, who are responsible for ZyXel support in Ireland. He reckons that it may not be an MTU problem, and that all the MTU problems with UTV have been with USB modems.

Anyhow, he's going to go through altering the settings tomorrow with me, and we'll take it from there.

BTW, he says that the <ipaddr> is probably not needed and the <mask bit> is not the subnet mask, but some other number like 24. (Was driving at the time he called, so could not talk for long).

Ro

Shouldn't have been on the phone at all while driving :mad:

Ro-76

Originally posted by mancman
Shouldn't have been on the phone at all while driving :mad:

Hard wired car kit!

Care to make a helpful suggestion?

Ro