In this final installment, let’s look at an alternative to BGP network statements, the “redistribute” command. For example, let’s say that our config looks like this: interface loopback 0 ip address 172.16.1.1 255.255.255.0 router bgp 65001 neighbor 1.2.3.4 remote-as 65002 redistribute connected no auto-summary What our router will do in this case is search its IP routing […]

This time, we’ll look at the behavior of network statements under BGP (Border Gateway Protocol). BGP peering relationships are configured manually using the BGP “neighbor remote-as” command, and the IP routing table is used to find the best route to a particular neighbor. Here’s a basic BGP configuration, with our router in BGP Autonomous System […]

Let’s continue with our discussion of techniques involving network statements and OSPF. As we previously discussed, we can get all of the interfaces running OSPF process 1 in Area 0 like this: router ospf 1 network 0.0.0.0 255.255.255.255 area 0 Another option is to assign the interfaces (or subinterfaces) to OSPF areas directly. For example, to get all of our […]

Now let’s examine network statements as used with OSPF. Refer to Figure 1: When using network statements with OSPF, the wildcard masks are required, as are area numbers. To get OSPF Area 0 running on all interfaces, we could do this: router ospf 1 network 192.168.1.1  0.0.0.0 area 0 network 172.16.1.1  0.0.0.0 area 0 network 10.1.1.1  0.0.0.0 area 0 network […]

Let’s look at some additional options that can be used with EIGRP network statements. Refer to Figure 1: In order to get EIGRP running on all interfaces, we could do this: router eigrp 1 network 192.168.1.0 network 172.16.0.0 network 10.0.0.0 As a result, the interfaces would advertise the following prefixes (remember that automatic route summarization is enabled […]

Let’s now take a look at the interplay between network statements and auto-summary with EIGRP. Refer to the example topology: To get EIGRP running on the Fa0/1, Fa0/2 and Fa0/3 interfaces, we’ll use the following configuration: router eigrp 1 network 172.16.0.0 network 10.0.0.0 Like RIPv2, EIGRP is a classless protocol that performs automatic route summarization by […]

Let’s now take a look at some additional techniques that can be used along with network statements to control routing advertisements. Refer to the example topology: Here’s a configuration we could use to get RIPv2 running on the Fa0/1, Fa0/2 and Fa0/3 interfaces: router rip version 2 network 172.16.0.0 network 10.0.0.0 Since we haven’t disabled […]

This time, we’ll take a look at the interaction between network statements, subnet masks and automatic route summarization with RIPv2. To get RIPv2 running on the Fa0/1, Fa0/2 and Fa0/3 interfaces, we’ll use the following configuration: router rip version 2 network 172.16.0.0 network 10.0.0.0 Note that Fa0/1 and Fa0/3 (the network 10.0.0.0 interfaces) are both using […]

Last time, we looked at the basic operation of RIP network statements. Now, let’s look at that topic in more detail.

To get RIPv1 running on the Fa0/1, Fa0/2 and Fa0/3 interfaces (but not on Fa0/0), we used the following configuration:

router rip

network 172.16.0.0

network 10.0.0.0

In this multi-part series, we’ll examine the effects of Cisco IOS “network” statements for various IP routing protocols. Let’s start with the IGPs (Interior Gateway Protocols)…