Configure routes and distribute routes by default in the network.

Configure routes and distribute routes by default in the network.
The automatic summary function for configuring the summary routing (VPC) is disabled by default in some later versions of IOS. In some earlier versions of ios, the automatic summary function is enabled by default, you can use show running-config | inc rotue to check whether it is enabled. Automatically summarize the routes that are generated by yourself (directly connected routes). Route entries that are forwarded (learned from other routers) are not automatically summarized; manual summarization can be performed on both the routes generated by the user and the learned routes. Self-dynamic summary may cause problems. For example, two vrouters automatically summarize the same primary vro entry (such as class A) to the same connected vro, the uplink router has two next hop ports for the same summary route entry, resulting in communication confusion (when the default ief is enabled, it is stream-by-stream (Source IP, destination IP, source port, destination port, and Protocol 5 are the same data stream), rather than process forwarding. If both automatic summary and manual summary are configured, both manual summary and automatic summary take effect. The stub of VPN is for vrouters, while OSPF is for regions. There are three management distances in the source image: 1. The source image is 90 in the source image and 2. The source image is 170 in the external image of the source image; 3. The total black hole route of the OSPF is 5 (you can view the route entry with the subnet mask show ). Summary route features: A detailed route is required locally to issue a summary route from the summary interface. The summary route does not disappear until the last route of the details disappears; the metri value of the summarized route takes the smallest metric value in the detailed route; A special route pointing to null is generated on the summarized router, the AD value of this special OSPF summary route is 5, which is used to prevent loops (if this device has a default route). Only the summary is sent without details. However, after using ip summary VPN, you can work with leak-map and ACL to leak some detailed routes (only for IOS 12.4 and later versions ). There are four ways to deliver default routes: 1. network 0.0.0.0: ip route 0.0.0.0 0.0.0.0 outbound interface (only the outbound interface can be used but not the next hop, imagine that the route is a local interface.) router VPN 100 network 0.0.0.0 (declaring all interfaces, the route of the above-thought-cost interface is also declared to the OSPF process, so other routers introduce D routes.) 2. redistribute static: ip route 0.0.0.0 0.0.0.0 access interface or the next hop router VPN 100 redistribute static other routers introduce DEX 3, ip summary vpn as number 0.0.0.0 0.0.0.0; because of the support of CIDR, different from RIP, you can directly summarize the route to 0.0.0.0 and then spread the route to other routers. You do not need to take another static default route for the summary from/0 to/0. 4. In Global mode, the default ip-network default route (the network in which the egress is located) // we do not recommend that you use this command in contrast to RIP. To use this command in OSPF, the following conditions must be met: 1. The interface IP address must be a primary class and cannot be a subnet (or use auto summary) 2. The interface must be advertised to the MongoDB. 3. When commands are issued, you must also enter the main class network number of this interface instance: R1 # sh ip routeCodes: C-connected, S-static, r-RIP, M-mobile, B-BGP D-VPN, EX-OSPF 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 exte Rnal type 2 I-IS, su-IS summary, L1-IS level-1, l2-IS level-2 ia-IS inter area, *-candidate default, U-per-user static route o-ODR, p-periodic downloaded static route Gateway of last resort is 172.16.1.2 to network 192.168.10.0 D * 192.168.10.0/24 [90/2681856] via 172.16.1.2, 00:48:14, Serial0/2 172.16.0.0/30 is subnetted, 2 subnetsD 172.16.1.4 [90/2681856] via 172. 16.1.2, 00:59:26, Serial0/2C 172.16.1.0 is directly connected, Serial0/2D * 0.0.0.0/0 [90/2681856] via 172.16.1.2, 00:34:42, serial0/2 R2 # sh run | sec eigrprouter VPN 50 network 172.16.1.0 0.0.0.3 network 172.16.1.4 0.0.0.3 network 192.168.10.0 network 0.0.0.0 auto-summary! Ip default-network 192.168.10.0ip forward-protocol ndip route 0.0.0.0 0.0.0.0 Serial0/3! R2 # sh ip routeCodes: C-connected, S-static, R-RIP, M-mobile, B-BGP D-VPN, EX-VPN 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 I-IS, su-IS summary, L1-IS level-1, L2-IS level-2 ia-IS inter area, *-candidate default, u-per-user static route o-ODR, P-periodic downloaded static route Gateway of last resort is 0.0.0.0 to network 0.0.0.0*192.168.10.0/24 is variably subnetted, 2 subnets, 2 masksC 192.168.10.0/30 is directly connected, Serial0/3D * 192.168.10.0/24 is a summary, 00:15:49, Null0 172.16.0.0/16 is variably subnetted, 3 subnets, 2 masksC 172.16.1.4/30 is directly connected, Serial0/0D 172.16.0.0/16 is a summary, 00:15:49, Null0C 172.16.1.0/30 is directly connected, serial0/1 S * 0.0.0.0/0 is directly connected, Serial0/3 R3 (config) # endR3 # sh ip * Mar 1 02:13:49. 395: % SYS-5-CONFIG_ I: Configured from console by consoleR3 # sh ip routeCodes: C-connected, S-static, R-RIP, M-mobile, B-BGP D-VPN, EX-OSPF 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 I-IS, su-IS summary, L1-IS level-1, l2-IS level-2 ia-IS inter area, *-candidate default, U-per-user static route o-ODR, p-periodic downloaded static route Gateway of last resort is 192.168.10.1 to network 0.0.0.0 C 192.168.10.0/24 is directly connected, Serial0/2C 192.168.0.0/24 is directly connected, loopback0C 192.168.1.0/24 is directly connected, Loopback1C 192.168.2.0/24 is directly connected, Loopback2C 192.168.3.0/24 is directly connected, Loopback3S * 0.0.0.0/0 [1/0] via 192.168.10.1