multiple tftp servers

[Eric Helm]

Is it possible to have multiple option tftp-server-name or next-server
for a single pool? I have a need to specify redundant tftp servers for
booting the clients. If the first server is down, use the second.

Thanks,
Eric

[Shane Kerr]

Post by Eric Helm
Is it possible to have multiple option tftp-server-name or next-server
for a single pool? I have a need to specify redundant tftp servers for
booting the clients. If the first server is down, use the second.

I don't know of any way to do this with options, but perhaps you can put
multiple A records in the DNS for the TFTP server name.

- --
Shane

[Simon Hobson]

Post by Eric Helm
Is it possible to have multiple option tftp-server-name or next-server
for a single pool? I have a need to specify redundant tftp servers for
booting the clients. If the first server is down, use the second.

No, the server field is defined to be a single address/path.

The only thing I can think of might be to use failover, have each
server give out it's own address as the TFTP server, and run some
sort of monitoring that turns off the dhcp service if the tftp
service is down. Actually, the tftp servers don't have to be on the
same boxes as the dhcp servers as long as you can tie together "no
tftp server' = "no dhcp server offering it as a boot server".

You could probably manage something similar with DNS. The client is
booting so will not have a cache of recent requests - so if you can
arrange for the dns to only resolve a fqdn to addresse(s) with
working tftp servers it would also achieve what you want.

Otherwise, you'll have to look as some form of high-availability stuff.

[David W. Hankins]

Post by Simon Hobson
The only thing I can think of might be to use failover, have each
server give out it's own address as the TFTP server, and run some
sort of monitoring that turns off the dhcp service if the tftp
service is down. Actually, the tftp servers don't have to be on the
same boxes as the dhcp servers as long as you can tie together "no
tftp server' = "no dhcp server offering it as a boot server".

Or run the tftp servers on the dhcp failover servers and have them
advertise only themselves.

[Simon Hobson]

Post by David W. Hankins

Post by Simon Hobson
The only thing I can think of might be to use failover, have each
server give out it's own address as the TFTP server, and run some
sort of monitoring that turns off the dhcp service if the tftp
service is down. Actually, the tftp servers don't have to be on the
same boxes as the dhcp servers as long as you can tie together "no
tftp server' = "no dhcp server offering it as a boot server".

Or run the tftp servers on the dhcp failover servers and have them
advertise only themselves.

IFF the tftp service is sufficiently reliable that "server running" =
"tftp service running" is a good enough approximation for the
requirements.

[Eric Helm]

Post by Simon Hobson

Post by Eric Helm
Is it possible to have multiple option tftp-server-name or next-server
for a single pool? I have a need to specify redundant tftp servers for
booting the clients. If the first server is down, use the second.

No, the server field is defined to be a single address/path.
The only thing I can think of might be to use failover, have each
server give out it's own address as the TFTP server, and run some
sort of monitoring that turns off the dhcp service if the tftp
service is down. Actually, the tftp servers don't have to be on the
same boxes as the dhcp servers as long as you can tie together "no
tftp server' = "no dhcp server offering it as a boot server".
You could probably manage something similar with DNS. The client is
booting so will not have a cache of recent requests - so if you can
arrange for the dns to only resolve a fqdn to addresse(s) with
working tftp servers it would also achieve what you want.
Otherwise, you'll have to look as some form of high-availability stuff.

Thanks, I think for now I'm gonna see how the 'use failover and each
server give out its own address for TFTP' option works.
Has anyone attempted to use anycast for TFTP services? How about anycast
for DHCP services?

/Eric

[David W. Hankins]

Post by Eric Helm
Has anyone attempted to use anycast for TFTP services?

Not that I'm aware of. I don't think TFTP rates high enough
on the 'critical services' list for most people.

Post by Eric Helm
How about anycast
for DHCP services?

There is at least one individual on this list who occaisionally
comes out, under the full moon after the appropriate sacrifice
has been made, and shares their experiences.

Try the dhcp-server archives at MARC.

[Eric Helm]

Post by David W. Hankins

Post by Eric Helm
Has anyone attempted to use anycast for TFTP services?

Not that I'm aware of. I don't think TFTP rates high enough
on the 'critical services' list for most people.

We actually have a new Fiber to the Home deployment that has the ONT use
TFTP to get their config files, similar to a DOCSIS model. If the ONT
doesn't get a config file, no Voice, Video or Data will work. So in our
case, TFTP is now critical.

But, I'll stick with using each failover server separate as the tftp
server and see how it goes, before I make things overly complicated.

/Eric