Differences between version 4 and previous revision of EIGRP.
Other diffs: Previous Major Revision, Previous Author, or view the Annotated Edit History
| Newer page: | version 4 | Last edited on Tuesday, August 17, 2004 5:01:35 pm | by LindsayDruett | Revert |
| Older page: | version 1 | Last edited on Tuesday, August 17, 2004 11:54:30 am | by LindsayDruett | Revert |
@@ -5,9 +5,86 @@
EIGRP is a routing protocol developed by [CiscoSystems] and has only been used on Cisco Equipment. This do not mean to say that someone can't develop Zebra to run EIGRP as another routing protocol.
[Information about EIGRP from Cisco Systems|http://www.cisco.com/en/US/tech/tk365/tk207/technologies_white_paper09186a0080094cb7.shtml]
----
-!!!EIGRP Terms
+!!EIGRP Configuration on Cisco Routers
+
+Global Router Configurations
+
+ Router(config)#__router eigrp__ ''<autonomous-system-number>''
+ ''- Starts the EIGRP process with the specified AS Number.''
+ Router(config-router)#__network__ ''<network> <wildcard-mask>'' __area __
+ ''- Shows the networks to be advertised.''
+ Router(config-router)#__no auto-summary__
+ ''- Given a hierarchial addressing design, disables to automatic summarization''
+ ''to the IANA network address.''
+ Router(config-router)#__eigrp stub <receive-only/connected/static/summary>__
+ ''- Used on small-capacity routers in a hub-and-spoke WAN environment.''
+ ''- The router has no neighbors and accesses the network through a distribution layer router.''
+ ''- Only a small routing table is required at the stub router,''
+ ''which is provided with a default route to the advertising ABR.''
+ Router(config-router)#__variance__ ''<multiplier-number>''
+ ''- Allows unequal-cost paths to load balance.''
+
+Interface Level Configurations
+
+ Router(config-if)#__ip summary-address eigrp__ ''<autonomous-system-number> <address> <mask>''
+ ''- Enables you to summarize the networks manually, having disabled automatic summarization.''
+ Router(config-if)#__bandwidth__ ''<Line-speed>''
+ ''- Issued at the interface level and a logical construct to determine the real bandwidth manually.''
+ Router(config-if)#__ip bandwidth-percent eigrp__ ''<autonomous-system-number> <percent>''
+ ''- Enables you to change the bandwidth percentage.''
+ ''- EIGRP, by default, will only take up to 50% of bandwidth.''
+ Router(config-if)#__ip hello-interval eigrp__ ''<autonomous-system-number> <seconds>''
+ ''- Changes how often the Hello is sent out of an interface.''
+ Router(config-if)#__ip hold-time eigrp__ ''<autonomous-system-number> <seconds>''
+ ''- This defines how long the router believes its neighbor to be alive withour hearing a hello from the neighbor.''
+ ''- This setting is not automatically changed when the hello-interval timer is changed.''
+
+Operation Verification Commands
+
+ Router#__show ip eigrp neighbors__
+ ''- Displays information drawn from the neighbor table.''
+ Router#__show ip eigrp topology__
+ ''- Displays information drawn from the topology table.''
+ Router#__show ip eigrp traffic__
+ ''- Shows the EIGRP traffic passing through the router.''
+ Router#__show ip protocols__
+ ''- Enables you to view the IP routing protocol configuration on the router.''
+ Router#__show ip route__
+ ''- Shows detailed information about the networks the router is aware and the preferred paths to those networks.''
+ ''- Also gives the next logical hop as the next step in the path.''
+
+Troubleshooting Commands
+
+''With troubleshooting using debug, if you're connected via the console port, turn on console logging (Router(config)#__logging console__) or if connected by virtual terminal, turn on the logging monitor (Router#__term mon__)''
+
+ Router#__debug eigrp packet__
+ ''- Shows the packets sent and received by the router.''
+ Router#__debug eigrp neighnors__
+ ''- Shows the Hello packets sent and received by the router and the neighbors discovered by this process.''
+ Router#__debug ip eigrp route__
+ ''- Shows dynamic changes made to the routing table.''
+ Router#__debug ip eigrp summary__
+ ''- Shows the process taken when a summary is changed on the router.''
+
+----
+!!Components of EIGRP
+
+__Protocol-Dependent Modules__
+*EIGRP functions as the routing protocol for IP, !AppleTalk, and IPX. A different routing table is maintained for each Layer 3 protocol.
+
+__RTP__
+*EIGRP uses both multicast and unicast addressing. Some of these packets are sent reliably using RTP, meaning that they require an acknowledgement. These packets are also sent with sequence numbers to make the transmission of data reliable. Hellos and ACKs do not require acknowledgement, but the incremental updates cannot be anticipated. Therefore, the update, query, and reply packets must be acknowledged by the receiving neighbor or the packet is retransmitted up to 16 times.
+
+__Neighbor Discovery and Recovery__
+*EIGRP operates between neighbors that share routing tables and information about the state of their connections. In this way, the routing protocol localizes as much information as posible, reducing the bandwidth and CPU requirements of the network and speeding up convergence.
+
+__DUAL__
+*EIGRP uses DUAL to maintain the network databases. It selects the shortest path to a destination and then maintains a backup path if available, making network convergence almost instantaneous. Using the terminology for EIGRP, the term ''successor'' refers to the path to a destination. The successor is chosen using DUAL from all of the known paths or feasible successors to the end destination. If the selected path dies for any reason, an alternate route is chosen from the feasible successors. If a feasible successor is found, the route stays in passive mode, and there is no disruption to the network. However, if an alternate path is not immediately available, the router queries its neighbors, placing the route in active mode.
+
+----
+
!!EIGRP Terms
|Neighbor|A router running EIGRP that is directly connected.
|Neighbor table|A list of every neighbor, including the IP address, the outgoing interface, the holdtime, smooth round-trip time (SRTT), and uptime, or how long since the neighbor was added to the table. The table is built from information on Hellos recieved from adjacent routers (neighbors)
|Route table|The routing table, or list of available networks and the best paths. A path is moved from the topology table to the routing table when a feasible successor is identified.
