Lab 9-1: RIPv2 Scenario
For this lab, GateD is running on ganymed, MRTd is running on castor and callisto, and Cisco IOS Software is running on scar. Figure 9-1 shows the topology.
Figure 9-1. RIPv2 Lab Topology
For a detailed log output of gated, send a kill ?SIGINT to the running gated process. You can also access the gated interactive interface via telnet localhost 616 or use the ripquery utility for RIP status information. A possible expansion of this setup would be to include routed, which was discussed thoroughly in Chapter 1, "Operating System Issues and Features?The Big Picture."
The lab uses regular interfaces, VLAN interfaces, alias addresses, and loopback addresses to demonstrate the independence of the routing engines from Layer 2 and virtual interfaces. This is also valid for WAN subinterfaces and tunnels of various kinds as long as the operating system is capable of providing a proper interface abstraction (virtual interface).
As you can see from the routing table outputs, the dynamic daemons internally use the concept of administrative distance (preference), but externally only the notion of metrics has relevance. Throughout this lab, we use RIPv2 multicast only. Example 9-1 shows the 224.0.0.9 multicast address in the netstat output (highlighted line); it is automatically added by the kernel.
NOTE
Per default, GateD turns RIP on. If you do not want to run the RIP module, you have to explicitly turn it off in the GateD configuration file with the command rip off (as presented in the GateD configuration in Example 9-1) or disable this behavior at compile time, as demonstrated in the GateD setup in Chapter 1.
Example 9-1. GateD RIPv2 Configuration and Output on Ganymed
[root@ganymed:~#] cat /etc/gated.cfg #rip off; rip on{ interface ne4 ne3 vlan0 ripin ripout version 2 multicast; }; [root@ganymed:~#] netstat -rn -f inet Routing tables Internet: Destination Gateway Flags Refs Use Mtu Interface default 111.11.117.1 UGS 1 3831 1500 ne5 127/8 127.0.0.1 UR 0 0 33224 lo0 127.0.0.1 127.0.0.1 UH 1 0 33224 lo0 192.168.1/24 link#1 UC -210 0 1500 ne3 192.168.1.1 52:54:5:e3:51:87 UHL 1 1916 1500 ne3 192.168.1.2 8:0:46:64:74:1b UHL 1 4615 1500 ne3 192.168.1.254 127.0.0.1 UGHS 0 0 33224 lo0 192.168.2/24 link#2 UC 0 0 1500 ne4 192.168.2.7 0:10:5a:c4:2c:4 UHL 5 2505 1500 ne4 192.168.7/24 192.168.2.7 UG 2 821 1500 ne4 192.168.13.0/29 192.168.2.7 UG 0 0 1500 ne4 192.168.14/24 192.168.1.1 UG 0 0 1500 ne3 192.168.17.0/29 192.168.2.7 UG 0 0 1500 ne4 192.168.44.1 192.168.44.1 UH 0 0 33224 lo1 192.168.45/24 192.168.2.7 UG 0 0 1500 ne4 192.168.80/24 link#16 UC 0 0 1496 vlan0 192.168.201.2 192.168.2.7 UGH 0 0 1500 ne4 111.11.117/24 link#3 UC 0 0 1500 ne5 111.11.117.1 0:5:9a:5b:23:fc UHL 1 0 1500 ne5 224.0.0.9 127.0.0.1 UH 1 1315 33224 lo0
Example 9-2 shows the advanced capabilities of the Linux ip tool. It presents the dynamic source that the routes were learned from via identifiers (Zebra, MRT, GateD), as well as the callisto MRTd configuration. The MRTd intrinsic routing table shows how cost (preference) is used internally with regard to the RIB (highlighted text). Note that connected and static routes are explicitly marked as Kernel in the MRTd global routing table (highlighted text). Example 9-3 presents the topology from castor's point of view.
Example 9-2. MRTd RIPv2 Configuration and Output on Callisto
[root@callisto:~#] ip route 192.168.201.2 via 192.168.14.254 dev eth0 proto mrt 192.168.44.1 via 192.168.45.254 dev eth1 proto mrt 192.168.17.0/29 via 192.168.14.254 dev eth0 proto mrt 192.168.13.0/29 via 192.168.14.254 dev eth0 proto mrt 192.168.7.0/24 via 192.168.14.254 dev eth0 proto mrt 111.11.117.0/24 via 192.168.45.254 dev eth1 proto mrt 192.168.2.0/24 via 192.168.45.254 dev eth1 proto mrt 192.168.80.0/24 via 192.168.45.254 dev eth1 proto mrt 192.168.1.0/24 dev eth1 scope link 192.168.1.0/24 dev ipsec0 proto kernel scope link src 192.168.1.1 192.168.14.0/24 dev eth0 scope link 192.168.45.0/24 dev eth1 proto kernel scope link src 192.168.45.1 127.0.0.0/8 dev lo scope link default via 192.168.1.254 dev eth1 [root@callisto:~#] netstat -rne Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.201.2 192.168.14.254 255.255.255.255 UGH 0 0 0 eth0 192.168.44.1 192.168.45.254 255.255.255.255 UGH 0 0 0 eth1 192.168.17.0 192.168.14.254 255.255.255.248 UG 0 0 0 eth0 192.168.13.0 192.168.14.254 255.255.255.248 UG 0 0 0 eth0 192.168.7.0 192.168.14.254 255.255.255.0 UG 0 0 0 eth0 111.11.117.0 192.168.45.254 255.255.255.0 UG 0 0 0 eth1 192.168.2.0 192.168.45.254 255.255.255.0 UG 0 0 0 eth1 192.168.80.0 192.168.45.254 255.255.255.0 UG 0 0 0 eth1 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 ipsec0 192.168.14.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 192.168.45.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo 0.0.0.0 192.168.1.254 0.0.0.0 UG 0 0 0 eth1 callisto-MRTd# sh config ! enable password ******** router rip network 192.168.1.0/24 network 192.168.14.0/24 redistribute connected redistribute static redistribute kernel ! route 0.0.0.0/0 192.168.1.254 debug all /var/log/mrtd.log 0 callisto-MRTd# sh rib 38 active prefixes 17 active generic attributes 13 active route heads 17 active route nodes 7 inet gateway(s)/nexthop(s) registered 0.0.0.0 on lo flags 0x8 (count 3) 0.0.0.0 on eth0 flags 0x8 (count 4) 0.0.0.0 on eth1 flags 0x8 (count 7) 0.0.0.0 on ipsec0 flags 0x8 (count 3) 192.168.1.254 on eth1 flags 0x2 (count 1264) 192.168.14.254 on eth0 flags 0x2 (count 668) 192.168.45.254 on eth1 flags 0x2 (count 19) callisto-MRTd# sh ip rip Routing Protocol is "rip" Listening on port 520 (socket 13) Sending updates every 30 seconds jitter [-50..50], next due in 20 seconds Triggered update and split horizon (no poisoned reverse) implemented Invalid after 180, hold down 120, flushed after 300 seconds Interface enabled: eth1 eth0 Number of routes in routing table: 12 Callisto-MRTd# sh ip rip routes P Pref Time Destination Next Hop f Cost Time * R 120 04:57:04 0.0.0.0/0 192.168.14.254 eth0 2 20 > S 1 05:04:39 0.0.0.0/0 192.168.1.254 eth1 1 ---- * R 120 05:04:30 192.168.1.0/24 192.168.45.254 eth1 2 2 > C 0 05:04:39 192.168.1.0/24 0.0.0.0 ipsec0 1 ---- R 120 00:00:20 192.168.2.0/24 192.168.14.254 eth0 3 20 > R 120 00:00:02 192.168.2.0/24 192.168.45.254 eth1 2 2 R 120 00:00:02 192.168.7.0/24 192.168.45.254 eth1 3 2 > R 120 04:57:06 192.168.7.0/24 192.168.14.254 eth0 2 20 R 120 00:00:02 192.168.13.0/29 192.168.45.254 eth1 4 2 > R 120 04:56:44 192.168.13.0/29 192.168.14.254 eth0 2 20 * R 120 05:02:39 192.168.14.0/24 192.168.45.254 eth1 3 2 > C 0 05:04:39 192.168.14.0/24 0.0.0.0 eth0 1 ---- R 120 00:00:02 192.168.17.0/29 192.168.45.254 eth1 4 2 > R 120 04:56:23 192.168.17.0/29 192.168.14.254 eth0 2 20 > R 120 00:00:02 192.168.44.1/32 192.168.45.254 eth1 2 2 * R 120 00:00:02 192.168.45.0/24 192.168.45.254 eth1 5 2 > C 0 00:47:47 192.168.45.0/24 0.0.0.0 eth1 1 ---- R 120 00:00:20 192.168.80.0/24 192.168.14.254 eth0 3 20 > R 120 00:00:02 192.168.80.0/24 192.168.45.254 eth1 2 2 R 120 00:00:02 192.168.201.2/32 192.168.45.254 eth1 4 2 > R 120 04:57:06 192.168.201.2/32 192.168.14.254 eth0 2 20 > R 120 00:00:02 111.11.117.0/24 192.168.45.254 eth1 2 2 callisto-MRTd# sh ip routes Number of Unique Destinations: 13, Number of Entries: 17 Status code: > best, * valid, i - internal, x - no next-hop, X - no install P Pref Time Destination Next Hop If Kernel > S 1 05:04:57 0.0.0.0/0 192.168.1.254 eth1 K R 120 04:57:22 0.0.0.0/0 192.168.14.254 eth0 >iC 0 05:04:57 127.0.0.0/8 0.0.0.0 lo K > C 0 05:04:57 192.168.1.0/24 0.0.0.0 ipsec0 K R 120 05:04:48 192.168.1.0/24 192.168.45.254 eth1 > R 120 00:00:20 192.168.2.0/24 192.168.45.254 eth1 > R 120 04:57:24 192.168.7.0/24 192.168.14.254 eth0 > R 120 04:57:02 192.168.13.0/29 192.168.14.254 eth0 > C 0 05:04:57 192.168.14.0/24 0.0.0.0 eth0 K R 120 05:02:57 192.168.14.0/24 192.168.45.254 eth1 > R 120 04:56:41 192.168.17.0/29 192.168.14.254 eth0 > R 120 00:00:20 192.168.44.1/32 192.168.45.254 eth1 > C 0 00:48:05 192.168.45.0/24 0.0.0.0 eth1 R 120 00:00:20 192.168.45.0/24 192.168.45.254 eth1 > R 120 00:00:20 192.168.80.0/24 192.168.45.254 eth1 > R 120 04:57:24 192.168.201.2/32 192.168.14.254 eth0 > R 120 00:00:20 111.11.117.0/24 192.168.45.254 eth1
Example 9-3. RTd RIPv2 Configuration and Output on Castor
castor-MRTd# sh config ! enable password ******** router rip network 192.168.2.0/24 network 192.168.7.0/24 network 192.168.80.0/24 redistribute connected redistribute static redistribute kernel ! route 0.0.0.0/0 192.168.2.254 debug all /var/log/mrtd.log 0 castor-MRTd# show timers Timer Master: Interval=(37), NextFire=(5) Timer RIP update timer: Interval 37 Base 30 Exponent 0 Jitter 0 [-50..50] Flags 0x20Timeleft 5 Timer kernel routes timeout timer: Interval 120 Base 120 Exponent 0 Jitter 0 [0..0] Flags
Example 9-4 shows a standard Cisco RIPv2 configuration, and Example 9-5 shows the corresponding Cisco Express Forwarding (CEF) output to demonstrate CEF's view of two equal-cost paths with per-packet load sharing configured (highlighted text). This CEF example should also be seen as a demonstration of the forwarding discussion in Chapter 8.
NOTE
This book does not contain a detailed CEF introduction. Consult Cisco.com for a better understanding of Example 9-5, which is presented only to show the correlation of the CEF and routing table.
Example 9-4. Cisco IOS RIPv2 Configuration and Output on Scar
scar# sh running-config ... router rip version 2 traffic-share min across-interfaces redistribute connected redistribute static passive-interface Serial0 passive-interface Serial1 passive-interface Serial2 passive-interface Serial3 network 192.168.7.0 network 192.168.14.0 maximum-paths 2 no auto-summary ... scar# sh ip rip database 0.0.0.0/0 auto-summary 0.0.0.0/0 redistributed [1] via 0.0.0.0, 192.168.1.0/24 auto-summary 192.168.1.0/24 [1] via 192.168.14.1, 00:00:04, Ethernet1 192.168.2.0/24 auto-summary 192.168.2.0/24 [1] via 192.168.7.7, 00:00:14, Ethernet0 192.168.7.0/24 auto-summary 192.168.7.0/24 directly connected, Ethernet0 192.168.13.0/24 auto-summary 192.168.13.0/29 redistributed [1] via 0.0.0.0, 192.168.14.0/24 auto-summary 192.168.14.0/24 directly connected, Ethernet1 192.168.17.0/24 auto-summary 192.168.17.0/29 redistributed [1] via 0.0.0.0, 192.168.44.0/24 auto-summary 192.168.44.1/32 [2] via 192.168.7.7, 00:00:14, Ethernet0 [2] via 192.168.14.1, 00:00:04, Ethernet1 192.168.45.0/24 auto-summary 192.168.45.0/24 [1] via 192.168.14.1, 00:00:04, Ethernet1 192.168.80.0/24 auto-summary 192.168.80.0/24 [1] via 192.168.7.7, 00:00:14, Ethernet0 192.168.201.0/24 auto-summary 192.168.201.2/32 redistributed [1] via 0.0.0.0, 111.11.117.0/24 auto-summary 111.11.117.0/24 [2] via 192.168.7.7, 00:00:14, Ethernet0 [2] via 192.168.14.1, 00:00:04, Ethernet1 scar# sh ip route Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area * - candidate default, U - per-user static route, o - ODR P - periodic downloaded static route Gateway of last resort is 192.168.7.7 to network 0.0.0.0 192.168.13.0/29 is subnetted, 1 subnets C 192.168.13.0 is directly connected, TokenRing0 C 192.168.14.0/24 is directly connected, Ethernet1 192.168.44.0/32 is subnetted, 1 subnets R 192.168.44.1 [120/2] via 192.168.14.1, 00:00:12, Ethernet1 [120/2] via 192.168.7.7, 00:00:06, Ethernet0 R 192.168.45.0/24 [120/1] via 192.168.14.1, 00:00:12, Ethernet1 192.168.201.0/32 is subnetted, 1 subnets C 192.168.201.2 is directly connected, Loopback0 R 192.168.80.0/24 [120/1] via 192.168.7.7, 00:00:06, Ethernet0 R 111.11.117.0/24 [120/2] via 192.168.14.1, 00:00:12, Ethernet1 [120/2] via 192.168.7.7, 00:00:06, Ethernet0 C 192.168.7.0/24 is directly connected, Ethernet0 192.168.17.0/29 is subnetted, 1 subnets C 192.168.17.0 is directly connected, TokenRing1 R 192.168.1.0/24 [120/1] via 192.168.14.1, 00:00:12, Ethernet1 R 192.168.2.0/24 [120/1] via 192.168.7.7, 00:00:06, Ethernet0 S* 0.0.0.0/0 [1/0] via 192.168.7.7 scar# sh ip route 192.168.44.1 Routing entry for 192.168.44.1/32 Known via "rip", distance 120, metric 2 Redistributing via rip Last update from 192.168.7.7 on Ethernet0, 00:00:01 ago Routing Descriptor Blocks: 192.168.14.1, from 192.168.14.1, 00:00:16 ago, via Ethernet1 Route metric is 2, traffic share count is 1 * 192.168.7.7, from 192.168.7.7, 00:00:01 ago, via Ethernet0 Route metric is 2, traffic share count is 1 scar# traceroute 192.168.44.1 Type escape sequence to abort. Tracing the route to 192.168.44.1 1 192.168.7.7 0 msec 192.168.14.1 4 msec 192.168.7.7 0 msec 2 192.168.44.1 4 msec 0 msec 0 msec
Example 9-5. Cisco IOS CEF Configuration and Output on Scar
scar# sh ip cef summary IP CEF with switching (Table Version 43), flags=0x0 30 routes, 0 reresolve, 0 unresolved (0 old, 0 new), peak 1 30 leaves, 18 nodes, 22496 bytes, 52 inserts, 22 invalidations 2 load sharing elements, 632 bytes, 2 references universal per-destination load sharing algorithm, id C5B17D30 3(0) CEF resets, 4 revisions of existing leaves Resolution Timer: Exponential (currently 1s, peak 1s) 2 in-place/0 aborted modifications refcounts: 4905 leaf, 4864 node Adjacency Table has 2 adjacencies scar# sh ip cef Prefix Next Hop Interface 0.0.0.0/0 192.168.7.7 Ethernet0 0.0.0.0/32 receive 192.168.1.0/24 192.168.14.1 Ethernet1 192.168.2.0/24 192.168.7.7 Ethernet0 192.168.7.0/24 attached Ethernet0 192.168.7.0/32 receive 192.168.7.7/32 192.168.7.7 Ethernet0 192.168.7.254/32 receive 192.168.7.255/32 receive 192.168.13.0/29 attached TokenRing0 192.168.13.0/32 receive 192.168.13.1/32 receive 192.168.13.7/32 receive 192.168.14.0/24 attached Ethernet1 192.168.14.0/32 receive 192.168.14.1/32 192.168.14.1 Ethernet1 192.168.14.254/32 receive 192.168.14.255/32 receive 192.168.17.0/29 attached TokenRing1 192.168.17.0/32 receive 192.168.17.1/32 receive 192.168.17.7/32 receive 192.168.44.1/32 192.168.14.1 Ethernet1 192.168.7.7 Ethernet0 192.168.45.0/24 192.168.14.1 Ethernet1 192.168.80.0/24 192.168.7.7 Ethernet0 192.168.201.2/32 receive 111.11.117.0/24 192.168.14.1 Ethernet1 192.168.7.7 Ethernet0 224.0.0.0/4 0.0.0.0 224.0.0.0/24 receive 255.255.255.255/32 receive scar# sh ip cef 192.168.44.1 192.168.44.1/32, version 40, per-packet sharing 0 packets, 0 bytes via 192.168.14.1, Ethernet1, 0 dependencies traffic share 1, current path next hop 192.168.14.1, Ethernet1 valid adjacency via 192.168.7.7, Ethernet0, 0 dependencies traffic share 1 next hop 192.168.7.7, Ethernet0 valid adjacency 0 packets, 0 bytes switched through the prefix scar# sh cef not-cef-switched CEF Packets passed on to next switching layer Slot No_adj No_encap Unsupp'ted Redirect Receive Options Access Frag RP 0 0 0 0 2987 0 0 0 scar#sh cef drop CEF Drop Statistics Slot Encap_fail Unresolved Unsupported No_route No_adj ChkSum_Err RP 0 0 0 4 0 0
Now you can replace the castor mrtd with the Zebra zebra and ripd (as shown in Example 9-6).
Example 9-6. Zebra RIPv2 Configuration and Output on Castor
[root@castor:~#] telnet localhost 2602 Trying 127.0.0.1... Connected to localhost (127.0.0.1) Escape character is '^]'. Hello, this is zebra (version 0.94). Copyright 1996-2002 Kunihiro Ishiguro. User Access Verification Password: castor-ripd# sh running-config Current configuration: ! hostname castor-ripd password zebra log file /var/log/ripd.log ! interface xl0 ip rip send version 2 ip rip receive version 2 ! interface ed0 ip rip send version 2 ip rip receive version 2 ! interface lo0 interface vlan8 router rip redistribute kernel redistribute connected redistribute static network 192.168.2.0/24 network 192.168.7.0/24 network 192.168.80.0/24 ! line vty ! end castor-ripd# sh ip protocols Routing Protocol is "rip" Sending updates every 30 seconds with +/-50%, next due in 8 seconds Timeout after 180 seconds, garbage collect after 120 seconds Outgoing update filter list for all interface is not set Incoming update filter list for all interface is not set Default redistribution metric is 1 Redistributing: kernel connected static Default version control: send version 2, receive version 2 Interface Send Recv Key-chain xl0 2 2 ed0 2 2 vlan8 2 2 Routing for Networks: 192.168.2.0/24 192.168.7.0/24 192.168.80.0/24 Routing Information Sources: Gateway BadPackets BadRoutes Distance Last Update 192.168.2.254 0 0 120 00:00:21 192.168.7.254 0 0 120 00:00:25 192.168.80.254 0 0 120 00:00:21 Distance: (default is 120) castor-ripd# sh ip rip Codes: R - RIP, C - connected, O - OSPF, B - BGP (n) - normal, (s) - static, (d) - default, (r) - redistribute, (i) - interface Network Next Hop Metric From Time K(r) 0.0.0.0/0 192.168.2.254 1 self K(r) 192.168.1.0/24 192.168.2.254 1 self C(i) 192.168.2.0/24 0.0.0.0 1 self C(i) 192.168.7.0/24 0.0.0.0 1 self K(r) 192.168.13.0/29 192.168.7.254 1 self K(r) 192.168.14.0/24 192.168.7.254 1 self K(r) 192.168.17.0/29 192.168.7.254 1 self K(r) 192.168.44.1/32 192.168.2.254 1 self K(r) 192.168.45.0/24 192.168.7.254 1 self C(i) 192.168.80.0/24 0.0.0.0 1 self K(r) 192.168.201.2/32 192.168.7.254 1 self K(r) 111.11.117.0/24 192.168.2.254 1 self
