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EIGRP Topology Table Entries

jgtheodor
Level 1
Level 1

Hello,

Yesterday i was looking one of our router's EIGRP Topology table and i found out some interesting entries as you can see below from the output of the show ip eigrp topology all-links command:

P 172.16.230.33/32, 0 successors, FD is Inaccessible, serno 0

P 10.100.104.112/32, 1 successors, FD is 3845120, serno 33721

via Rstatic (3845120/0)

P 172.16.230.42/32, 1 successors, FD is 20512000, serno 27610

via Rconnected (20512000/0)

P 172.16.230.40/30, 1 successors, FD is 20512000, serno 27611

via Connected, Serial2/3

P 10.100.20.201/32, 1 successors, FD is 3845120, serno 33712

via Rstatic (3845120/0)

via 172.16.230.246 (3847680/28160), Serial4/3.100

Can anyone explain to me what does the entry "via Rstatic" mean? The relevant entries are static route on the same router. I also noticed the line with the phrase "FD is Inaccessible"...What does this mean? Finally the word "serno" at the end os some lines is does indicate something?

Thanks in advance!

1 Accepted Solution

Accepted Solutions

ruwhite
Level 7
Level 7

"FD is Inaccessible" means there is a route in the table with a better administrative distance, so while EIGRP has a route, it's not installing the route in the local RIB.

The "serno" is the serial number of the topology table entry. This is a local number used in the reliable transmission of topology table entries between EIGRP neighbors. When a route is transmitted, the sending router keeps a list of the serial numbers contained in the packet. When the packet is acknowledged, this list of serial numbers is used to modify the states of the affected routes in the topology table.

:-)

Russ

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4 Replies 4

royalblues
Level 10
Level 10

Rstatic would mean that the route has been redistributed into EIGRP

FD is inaccessible -- This means the prefix entry in the routing table is not via EIGRP though EIGRP has lernt it but the RT chose to install the route by some other routing protocol (static,connected,ospf etc)

serno is a pointer to a doubly linked serial number for the route. This is used by an internal (and proprietary) mechanism for tracking the correct route information in a rapidly changing topology.

HTH

Narayan

Richard Burts
Hall of Fame
Hall of Fame

John

In the EIGRP topology table the Rstatic indicates a prefix learned by EIGRP through redistribution of static routes. "FD is Inaccessible" means that the metric for the prefix is set to infinity and that the router should not forward packets to this table entry.

HTH

Rick

HTH

Rick

evsrajatgupta
Level 1
Level 1

Hi,

See this link it will help you

http://www.informit.com/articles/article.aspx?p=27839

Please rate

ruwhite
Level 7
Level 7

"FD is Inaccessible" means there is a route in the table with a better administrative distance, so while EIGRP has a route, it's not installing the route in the local RIB.

The "serno" is the serial number of the topology table entry. This is a local number used in the reliable transmission of topology table entries between EIGRP neighbors. When a route is transmitted, the sending router keeps a list of the serial numbers contained in the packet. When the packet is acknowledged, this list of serial numbers is used to modify the states of the affected routes in the topology table.

:-)

Russ

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