Bug#537271: debian-installer: network may not be usable as soon as link is up
On Thursday, July 16, 2009 05:39:24 pm you wrote:
> the debian-installer seems to assume that the network is usable as soon
> as the link comes up, which may not be the case if the 802.1d spanning
> tree protocol is in use, in which case it can be up to ~30 seconds
> before the switch port will forward ethernet frames.
>
> i've noticed that trying to preseed a network install on a machine
> attached to an STP-enabled switch usually fails since as soon as the
> network link is up, d-i attempts to perform a reverse DNS lookup and
> fetch the preseed.cfg file via HTTP, both of which timeout and fail
> before the switch port the machine is attached to enters the forwarding
> state.
>
> a nice strategy to detect if the network is usable might be to send ARP
> requests for the default gateway's IP address and consider the network
> "up" only after the default gateway is reachable. it looks like there
> is a busybox version of the arping utility that could help accomplish
> this.
Quick & dirty workaround if enabling arping in busybox (or implementing the
same in C in netcfg itself) is not an option, may also be to simply increase
the number of ARP retries.
echo 60 > /proc/sys/net/ipv4/neigh/eth0/mcast_solicit
--
Yours sincerely,
Floris Bos
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