tech-net archive


Re: Retiring dhclient

On 11-11-24 01:10 PM, Joerg Sonnenberger wrote:
Yes. It does mean that there is a window in which unplugging the cable
and plugging it back won't be noticed, but it is my believe that is more
acceptable than the current status quo.

Does anyone know how long PHY resets for affected cards take?

Just a nit: The PHY shouldn't be resetting, MTU is at the MAC layer in Ethernet.

I disagree with not showing the link down for two reasons.
1) 10GigE has a Reconciliation Sublayer. If we go down (Local Fault) then the far end will go to Remote Fault and go down as well. This causes all kinds of confusion when one end is saying the other went down and the faulty end claims it didn't go down at all.

2) Various routing protocols that are link state driven - these should get notified of every link transition. In this case the link is unlikely to be active in routing but this change would affect all link down glitches.

Now I do agree that the last think you want is to end up going around in circles with the DHCP response driving a new MTU which resets the MAC and that triggers a new DHCP request. I believe that should be handled at the application level i.e. in dhcpd with a link down tolerance. It's the same idea but done in each application rather than the stack itself.

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