Maximum MTU for PPPOE
There are two clients Cisco AnyConnect[?] and Cisco VPN Client (a lot older) that I know of
I'm using the old one (despite the fact my company wants me to use the newer one!).
The MTU is set to 1300 at install time and it does install a service as well - the service doesn't appear to overwrite the settings...
As you can see from the above, I've set my MTU manually to 1500 (IDX 11) - and I'm connected to work on IDX 18.
I've got two connections I use - only one of those is currently working with the MTU set to 1500.
Does it make a great deal of difference in terms of performance? I wouldn't say it made a massive difference since the whole idea is to use a lower MTU to avoid fragmentation (which is what slows things down), but obviously you're not getting the full throughput.
You can fix this by doing the following from a command window (you need to "run as Admistrator").
My wired connection has a name "Ethernet" - yours might be different.
(You need to reboot for the setting to take effect)
If you want to set it back you just change "mtu=1500" to "mtu=1300" in the example above...
PS I hate the Cisco VPN software with a passion!
*edit*
Added details on how to set the MTU...
I'm using the old one (despite the fact my company wants me to use the newer one!).
The MTU is set to 1300 at install time and it does install a service as well - the service doesn't appear to overwrite the settings...
C:\Users\Rob>netsh int ip show int
Idx Met MTU State Name
--- ---------- ---------- ------------ ---------------------------
1 50 4294967295 connected Loopback Pseudo-Interface 1
11 10 1500 connected Local Area Connection
13 10 1500 disconnected Local Area Connection* 9
18 10 1300 connected Local Area Connection 2
As you can see from the above, I've set my MTU manually to 1500 (IDX 11) - and I'm connected to work on IDX 18.
Does it make a great deal of difference in terms of performance? I wouldn't say it made a massive difference since the whole idea is to use a lower MTU to avoid fragmentation (which is what slows things down), but obviously you're not getting the full throughput.
You can fix this by doing the following from a command window (you need to "run as Admistrator").
My wired connection has a name "Ethernet" - yours might be different.
C:\Windows\system32>netsh int ip show int
Idx Met MTU State Name
--- ---------- ---------- ------------ ---------------------------
3 10 1300 connected Ethernet
1 50 4294967295 connected Loopback Pseudo-Interface 1
4 20 1300 disconnected Wi-Fi
C:\Windows\system32>netsh int ipv4 set subinterface "Ethernet" mtu=1500 store=persistent
Ok.
C:\Windows\system32>netsh int ip show int
Idx Met MTU State Name
--- ---------- ---------- ------------ ---------------------------
3 10 1500 connected Ethernet
1 50 4294967295 connected Loopback Pseudo-Interface 1
4 20 1300 disconnected Wi-Fi
(You need to reboot for the setting to take effect)
If you want to set it back you just change "mtu=1500" to "mtu=1300" in the example above...
PS I hate the Cisco VPN software with a passion!
*edit*
Added details on how to set the MTU...
Quote from: Anotherone For those techies that may want to have a play with the 2704n, see http://community.plus.net/forum/index.php/topic,137629.0.html
Also, in ADSL mode it definitely defaults to 1500 MTU (when supplied in ADSL configuration). Other variations yet to be tested.
I retract that, as that was what was in the config I saved before I went on-line after doing a factory reset.
See here and reply #127.
Quote from: 11110_110 Where was I, oh yes.. I'm getting 1478 from here
My ping tests on the other side of the Wan are giving me 1450 which is a little confusing as the test above adds the +28 for overheads into the test results by default.
Hmm interesting, you did that test on Fibre, and I got the same result on ADSL. It's correct as well. I'd forgotten I'd set my network that way.
And the 2704n is 1492.
I'm not sure why you are getting your 1478 though, not following it at present
1492 is the theoretical max for PPPoE (just in case anyone reading has got confused).
As above, my FTTC connected 2704n is showing an MTU of 1478, thats as supplied, so I'm guessing that is what the router ships with from plusnet ?
I was merely looking for the reason why my MTU was showing 1478 in the first place. Maybe people should read the whole thread
I was merely looking for the reason why my MTU was showing 1478 in the first place. Maybe people should read the whole thread