Ethernet Backbone and Seed Routers



Here are some questions and answers about supporting AppleTalk on a corporate
Ethernet backbone -- specifically, a group-managed, Macintosh-based Internet
router which would be the sole seed router for the Ethernet.
Q) Can all third-party routers that support the AppleTalk Phase 2 protocol
accept seeding from the AppleTalk Internet Router?

A) All third-party routers that Apple Tech Comm is aware of can receive their
network information from the AppleTalk Internet Router. It is best to
confirm this information with the manufacturer of the routers that your
account plans to use. Remember, there must be a seed router on every
physical cable.


Q) What is the effect on the network if the seed router goes down for 24 hours
or more?

A) Nothing, other than losing the ability to route packets to the networks on
the other side of the seed router. If a router that depends on the seed
router goes down, when it attempts to come back up it will not get a network
number for the physical cable common to both routers and will not route.


Q) What is the effect if a user brings up a non-seed router with different
network numbers and zone names?

A) All the routers of which Apple Tech Comm is aware will report that there is
a network number and/or zone name conflict and will not come up. If a
router did allow you to enter with an incorrect zone or network number
information, many problems would occur. Network devices may not appear, or
they may appear in different zones. Packets will be lost and many network
errors will be generated.


Q) If I need to expand the seed routers network range and zone list, must I
bring the other routers down for the update?

A) Yes, the seed router will attempt to run and notice that the network number
range and/or zone name is different and report an error regarding the
conflict. This necessitates bringing down the other routers on the same
physical cable that get their network information from the seed router. As
usual, the seed router must be up and running before the other routers are
brought up.


Published Date: Feb 18, 2012