Recovering from multiple routers advertising routes
At my office there are a bunch of engineers (including myself) who like to
experiment with routers. In one case, an engineer connected one interface
of the Cisco router to the general office network and turned on IPv6 with a
site-local address. My Linux and WinXP boxes received the router
advertisement and set themselves up with the new site-local address,
sending all traffic to the new router. In the second case, an engineer
powered up a Cisco router which had IPv6 configured previously and
connected two of the interfaces to the network. My IPv6-capable boxes saw
two router advertisements and wanted to send all IPv6 traffic via this
router.
Fixing the routing/addressing problem created by these routers was easy to
fix on my Windows XP laptop by rebooting the laptop. I didn't want to
reboot my Linux boxes and tried to figure out how to undo the routing
changes caused by the router advertisements. "route" failed in my attempts
to remove the /64 blocks. I ultimately got rid of the routing problems by
rebooting the Linux systems.
My questions:
- What is the recommended set-up for Linux servers which are not set-up as
routers? In my opinion, allowing a server to add addresses/routing every
time a router starts advertising rogue addressing blocks is dangerous and
should be avoided.
-- How is an IPv6 default route added in Debian?
-- Various resources maintain that adding a default route in Linux is
problematic and should be avoided. Is this still the case in general
and/or with Linux?
- How does one recover from receiving a router advertisement from a rogue
router without rebooting the Debian Linux system?
-- Are there any IPv6-specific limitations in the "route" command?
-- Are there any lower-level ways of removing IPv6 routes without "route"?
- Finally, a general question which perhaps isn't appropriate for this
list, but I'm interested in the scope of the problem. One of the engineers
who introduced a rogue router argued that allowing a router to confuse the
IPv6 network with router advertisements is a major flaw in the protocol.
Is this engineer's statement valid or is protocol just fine and the
implementation broken?
Bill Cerveny
Internet2
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