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Re: Cisco DOCS confusion posted 09/20/2008
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This is a terrible example in the DOC CD. I cannot understand why it exists in the DOC CD!!! It is just a terriblly wrong example, in my opinion.
(1) I thought all three routes were advertised by "network" command under router eigrp 1
No, you are not correct. All three routes are advertized by the redistribute static command.
In the EIGRP, similar to all IGP, the network command is to specify what interface(s) take part in the routing protocol. It is not to advertize the subnets specify by that statement.
EIGRP also requires you to put the wildcard mask. If you do not, then EIGRP a classfull network is specified.
In the example
router eigrp 1 network 10.10.10.0
is the same as
router eigrp 1 network 10.0.0.0
or
router eigrp 1 network 10.0.0.0 0.255.255.255
In EIGRP there's one special case where the network statement also advertizes the route, is when you do network 0.0.0.0 and you have a static default route. In this case, the network 0.0.0.0 statement also enables EIGRP on all interfaces as well.
router eigrp 1 network 0.0.0.0 ip route 0.0.0.0 0.0.0.0 null0
In the DOC CD examle, these network statments for 192.168.0.0 and 10.10.10.0 have nothing to do with the usage of distribute-list to control redistribution from Static to EIGRP!
(2) the access-list 3 permit 192.168.x.0 should have wildcard mask 0.0.0.255?
You are right. Doc CD is wrong.
(3) I thought all three routes were redistributed by the *redistribute static* router configuration?
You are right. I do not know what they meant to blocked here ;) Maybe they mean "deny 10.10.10.0 0.0.0.255" to block the last one (???!!!)
(4) what does the *distribute-list 3 out static* command do in this case?
Nothing, unless they change the ACL 3 to block one of the three subnets. In that case, the one blocked by the ACL will not be advertized into EIGRP.
--- On Sat, 9/20/08, CCIE unnumbered <ccie.unnumbered@xxxxxxxxx> wrote:
From: CCIE unnumbered <ccie.unnumbered@xxxxxxxxx> Subject: Cisco DOCS confusion To: ccielab@xxxxxxxxxxxxxx Date: Saturday, September 20, 2008, 3:20 PM Dear Groupstudy Experts:
Please find a digest from http://www.cisco.com/en/US/docs/ios/iproute/configuration/guide/irp_ip_prot_indep_ps6350_TSD_Products_Configuration_Guide_Chapter.html#wp1057083 in the end of this message, and help me explain the description of the section. (1) I thought all three routes were advertised by "network" command under router eigrp 1 (2) the access-list 3 permit 192.168.x.0 should have wildcard mask 0.0.0.255? (3) I thought all three routes were redistributed by the *redistribute static* router configuration? (4) what does the *distribute-list 3 out static* command do in this case?
Static Routing Redistribution Example
In the example that follows, three static routes are specified, two of which are to be advertised. The static routes are created by specifying the *redistribute static* router configuration command and then specifying an access list that allows only those two networks to be passed to the EIGRP process. Any redistributed static routes should be sourced by a single router to minimize the likelihood of creating a routing loop.
Router(config)# *ip route 192.168.2.0 255.255.255.0 192.168.7.65 *
Router(config)# *ip route 192.168.5.0 255.255.255.0 192.168.7.65 *
Router(config)# *ip route 10.10.10.0 255.255.255.0 10.20.1.2 *
Router(config)# *! *
Router(config)# *access-list 3 permit 192.168.2.0 0.0.255.255 *
Router(config)# *access-list 3 permit 192.168.5.0 0.0.255.255 *
Router(config)# *access-list 3 permit 10.10.10.0 0.0.0.255 *
Router(config)# *! *
Router(config)# *router eigrp 1 *
Router(config-router)# *network 192.168.0.0 *
Router(config-router)# *network 10.10.10.0 *
Router(config-router)# *redistribute static metric 10000 100 255 1 1500 *
Router(config-router)# *distribute-list 3 out static *
Thanks, -- CCIE unnumbered
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