Automatically Recover from Error Conditions
By default, ports put into the errdisable state must be re-enabled manually. This is done by issuing the shutdown command in interface configuration mode, followed by the no shutdown command. Before you re-enable a port from the errdisable condition, you always should determine the cause of the problem so that the errdisable condition doesn’t occur again. You can decide to have a switch automatically reenable an errdisabled port if it is more important to keep..
The second branch in the local computation logic causes the EIGRP router to ask its neighbors about their current best route to a subnet, hoping to find an available, loop-free alternative route to that subnet. When no FS route is found, the EIGRP router goes active for the route. Going active is jargon for the process of changing a route’s status to active. Once the router is active, EIGRP multicasts Query messages to its neighbors, asking the neighbors if they have a vali..
Level 1 router summarization is done only for external routes (redistributed routes from other protocols) because the level 1 router does not receive any routes from the level 2 routers. As such, there is no need to summarize routes from level 2 routers—you can summarize both level 1 and external routes in level 2. External routes can be summarized only at the redistributing router. After the LSP is originated, it cannot be summarized. Summarizing of external ..
RSVP is a per-flow protocol that requests a bandwidth reservation from every node in the path of the flow. In its simplest form, RSVP is a unidirectional protocol, so if a bidirectional reservation is required for a flow, both endpoints must initiate a request for a reservation. Basic RSVP protocol operation is shown in Figure 8-1 and its configuration in Example 8-1. The endpoints, or other network devices on behalf of the endpoints, send unicast signaling messages to estab..
You can look at the attributes for a tunnel with the show interface command. Router1#show interface Tunnel5 And the easiest way to determine if a tunnel is operational is simply to use a PING test to either the send ICMP packets through the tunnel or to its destination address: Router1#ping 192.168.66.6 Router1#ping 172.22.1.4 You can use the standard show interface command on a tunnel interface to see a considerable amount of useful information about it: Router1#show in..
