Re: [nznog] to xtra.co.nz sysadmins
thanks to everyone who replied. I was told by my ISP to change the ppp MTU from the default of 1514 to 250 a week ago because I was having problems connecting to another machine so I changed it to 512 just now and that enables me to view those sites again and access the other machine. regards to all tom PS I wasn't pointing the finger, I assumed knossos was correct but you're right about not troubleshooting properly, I only looked up the ns for yellowpages, not telecom. my bad :((
no, orcon told me to use 250 and it seems 1514 is the default in linux. I had no problems connecting to anything with it set at 1514 except this other linux box, also on orcon dial up. what should it be? tom
I was told by my ISP to change the ppp MTU from the default of 1514 to 250
Xtra told you to use an mtu of 250 ???? And they told you that the default was 1514 ???
ohhhkaaay........
-Richard
On 24 Nov 2004, at 22:11, admin wrote:
no, orcon told me to use 250 and it seems 1514 is the default in linux.
The MTU usually depends on the frame size that can be accommodated by an interface. There is no useful "default" MTU. I seem to remember hearing from someone that Linux includes the encapsulating frame headers in its calculations when it interprets an MTU, which would make 1514 make sense for Ethernet. Kind of. Except that (MAC dest + MAC source + MAC type + CRC) == 18 bytes. I don't know much about Linux, though. I tend to avoid it in favour of real operating systems. [*] As to 250 bytes, RFC 1122 says: Since nearly all networks in the Internet currently support an MTU of 576 or greater, we strongly recommend the use of 576 for datagrams sent to non-local networks. That seems like reasonable advice, particularly if you expect to have to deal with fragmentation. However, in general, if you reduce your MTU below 1500 bytes you can expect all the inexpertly-firewalled, pMTUd-enabled servers of the world to stop sending you packets, sooner or later. Joe [*] I am running away quickly now.
On Thu, 25 Nov 2004, Joe Abley wrote:
[*] I am running away quickly now.
Thats ok joe, we know you are a windows tech from way back.. anyway, getting this back OT, do they sell beer where you are ? up for a round in a few months time ? -- Steve.
participants (5)
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admin -
Joe Abley -
Juha Saarinen -
Richard Patterson -
Steve Phillips