Re: Redundant links between subnets


At least for EIGRP, using the network statment for neighbours has a
nasty side-affect.


From Cisco EIGRP FAQ:

"What does the neighbor statement in the EIGRP configuration section
do?


A. The neighbor command is used in EIGRP to define a neighboring
router with which to exchange routing information. Due to the current
behavior of this command, EIGRP exchanges routing information with the
neighbors in the form of unicast packets whenever the neighbor command
is configured for an interface. EIGRP will stop processing all
multicast packets coming inbound on that interface. Also, EIGRP stops
sending multicast packets on that interface.

The ideal behavior of this command would be for EIGRP to start
sending EIGRP packets as unicast packets to the specified neighbor, but
not stop sending and receiving multicast packets on that interface.
Since the command does not behave as intended, the neighbor command
should be used carefully, understanding the impact of the command on
the network."

.

Relevant Pages

  • [NEWS] Authenticated EIGRP DoS and Information Disclosure
    ... Get your security news from a reliable source. ... Authenticated EIGRP DoS and Information Disclosure ... using this method the FX EIGRP/ARP DoS attack can be ... claiming that it's neighbor is down, ...
    (Securiteam)
  • [Full-disclosure] Unauthenticated EIGRP DoS
    ... We have used our custom EIGRP packet generator written on Perl to evaluate the security of the EIGRP routing protocol. ... we have discovered a novel selective single peer - directed DoS attack employing the EIGRP "Goodbye Message". ... be sent to a peer claiming that it's neighbor is down, ... 65534: Neighbor 192.168.66.111 (Ethernet0/0) is down: retry limit exceeded ...
    (Full-Disclosure)
  • a Strange Problem of EIGRP
    ... My client's network was interrupted recently because his ... router both in eigrp as 1 and eigrp as 65000. ... my client manually clear eigrp neighbor with R3. ...
    (comp.dcom.sys.cisco)
  • Re: a Strange Problem of EIGRP
    ... So this problem lead to a Power problem not Eigrp problem. ... know my client afraid of HQ's administrator. ... AS 65000 routes still could recover. ... my client manually clear eigrp neighbor with R3. ...
    (comp.dcom.sys.cisco)
  • Re: Help - URL opening problem
    ... command and some other deals, like trying to open a Word .doc. ... >> Orville Noah wrote: ... My neighbor called me this ... >> I'm not Wesley, but I'm sure he'd join with me in saying that this ...
    (microsoft.public.windowsxp.basics)