MTU and Dynamic DNS

[jolab]

Hi,

Apart from my continual disconnection issues that have arisen since the network upgrade end 2010 (5 years seamless operation till then) I am getting another funny error.

With the network upgrade, Iburst also updated their network MTU to 1392. Great.
Problem is that dynamic DNS does not work with this MTU. It only updates with MTU set @ 1352. Router handles this so not a PC MTU conflict. Changing the MTU to 1352 causes other problems with specific sites on the internet and understandably so due to packet fragmention etc. If I need to access a problematic site I have to change the MTU to 1392 (killing dyndns) - check the site and then switch back to 1352 enable dyndns.

Anyone else seeing this?

J

 

[r00igev@@r]

Hi,

Apart from my continual disconnection issues that have arisen since the network upgrade end 2010 (5 years seamless operation till then) I am getting another funny error.

With the network upgrade, Iburst also updated their network MTU to 1392. Great.
Problem is that dynamic DNS does not work with this MTU. It only updates with MTU set @ 1352. Router handles this so not a PC MTU conflict. Changing the MTU to 1352 causes other problems with specific sites on the internet and understandably so due to packet fragmention etc. If I need to access a problematic site I have to change the MTU to 1392 (killing dyndns) - check the site and then switch back to 1352 enable dyndns.

Anyone else seeing this?

J

The following works 100%: TomatoUSB NoUSB Standard and VPN versions enabled with dyndns and opendns and an mtu of 1392. What is your router firmware version?

 

[marlboro]

DynDNS works for me on iBurst even after they changed the MTU.

 

[jolab]

The following works 100%: TomatoUSB NoUSB Standard and VPN versions enabled with dyndns and opendns and an mtu of 1392. What is your router firmware version?

I have 2 routers (not running concurrently) - both display the same behaviour. Both are linksys WRT54G's
V2.2 - running latest DD-WRT
V5.0 - running latest native linksys firmware

Have tried the Tomato FW - didn't like it, so reverted back to DDWRT some time ago.

One thing I did not mention is that it does work with 1392 - but only about 1 out of 20 attempts and when it eventually works, the connection does not stay up long enough to make use of it, - rinse repeat.

Have been wondering is one of the towers in my area (that I get flung to) might not have been configured correctly and is causing my disconnect problems and now this...

 

[r00igev@@r]

I have 2 routers (not running concurrently) - both display the same behaviour. Both are linksys WRT54G's
V2.2 - running latest DD-WRT
V5.0 - running latest native linksys firmware

Have tried the Tomato FW - didn't like it, so reverted back to DDWRT some time ago.

One thing I did not mention is that it does work with 1392 - but only about 1 out of 20 attempts and when it eventually works, the connection does not stay up long enough to make use of it, - rinse repeat.

Have been wondering is one of the towers in my area (that I get flung to) might not have been configured correctly and is causing my disconnect problems and now this...

I'll have the guys in Cape Town check.

 

[jolab]

I'll have the guys in Cape Town check.

Also - yesteday I was able to download more than 10GB throughout the day. 2 disconnects only later in the evening but otherwise it was bliss. Today it could not keep a connection for longer than 2 minutes and unable to update DynDNS on 1352 OR 1392... My cap is not exceeded and I have not moved my modem since the previous day when all was well.