From: Michael Richardson <mcr@sandelman.ca>
To: linux-ppp@vger.kernel.org
Subject: Re: MTU strategies
Date: Tue, 08 Dec 2015 22:12:05 +0000 [thread overview]
Message-ID: <1708.1449612725@dooku.sandelman.ca> (raw)
In-Reply-To: <5665C351.3020500@seiner.com>
Yan Seiner <yan@seiner.com> wrote:
> I have a question on MTU size strategies.
> I have a router that terminates a VPN. The router connects via ppp to
> my ISP. I have a physical interface, with a virtual interface for
> pppoe, and a tun interface for the VPN that runs over the pppoe
> interface.
> The physical interface (eth0) has a MTU of 1500.
> The pppoe interface has an MTU of 1492.
> The vpn interface has an MTU of 1452, a figure I picked somewhat
> arbitrarily, assuming a 40 byte overhead for the vpn.
> My question is then for the other interfaces on the router that face
> the LAN and the DMZ. Should these be set to 1492 or 1500?
If the VPN won't be involved, then 1492 is the best bet.
PMTU is *supposed* to take care of all of this, but...
> And my other question is for the DHCP clients. Should they be set to
> 1492 (and the one host that uses the VPN should be set to 1452)?
The DHCP client should receive 1492 from the server, and set it on the
interface.
prev parent reply other threads:[~2015-12-08 22:12 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-07 17:35 MTU strategies Yan Seiner
2015-12-08 22:12 ` Michael Richardson [this message]
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