Error-prone configuration of Huawei Routers

During configuration of some large networks, due to a lot of work done, it is inevitable that configuration errors will occur. This article summarizes the common configuration errors of routers in depth, to avoid unnecessary time waste.

1. Ignore filtering when re-allocating routes. When re-allocating routes to routers, You need to enable the routing filtering function to delete paths that may cause loops. Therefore, if you do not apply a routing filter policy, errors are usually caused.

However, it is complicated for administrators to filter out a large network without complete global information, and the path here or there may be missed.

Therefore, the best way to avoid this problem is to try not to re-allocate routes. In fact, re-allocating routes is usually a bad strategy, in fact, we can find the correct solution to the problem without re-assigning the route.

2. Neighbor parameters that do not match in OSPF. To establish an association with a neighbor node, OSPF-based routers usually need to maintain several common parameters. These parameters include authentication, Region ID, mask, Hello interval, and router extinction interval. In actual network deployment, incorrect neighbor parameters, such as nonstandard configurations and incorrect passwords, may cause node Association failure.

For such errors, the network administrator can easily find out whether the errors are caused by mismatched neighbor parameters by Debugging commands related to OSPF joining and which parameters are incorrect, then modify.

3. When re-assigning a route, the subnet password is missing. When re-assigning a route to an OSPF-based network, another common error is that several paths are lost, this is usually because the Administrator network has a subnet keyword attached to the end of the reallocation command. For example, for a Cisco router, The subnet keyword is critical when OSPF re-allocates a subnet route. If there is no keyword with the subnet mask, OSPF only re-allocates network routes outside the subnet.

4. If you forget to configure the measurement index, if you find that all the path information is lost when you re-allocate the route in the network based on the VPN protocol, it is very likely that the Administrator forgets to configure the route measurement indicator and sets the route measurement function by default, and forcibly requires the Administrator to manually set it.

Therefore, if the Administrator does not set a measurement indicator, re-assigning the route will not succeed. At the same time, it can be seen that when the network is used, re-routing is not a reasonable choice.

5. The configuration of the OSPF measurement indicator is unreasonable. It is usually difficult to adjust the measurement indicator reasonably to distribute the network traffic reasonably. In general, sending business traffic over Internet VPN may be more reasonable than using a low-bandwidth Frame Relay line, so more traffic should be allocated to the former.

Bandwidth and latency indicators seem easy to set. However, for administrators, if they want to add all the metrics they have set to the target function formula for weighting, it is difficult to assess whether the expected traffic distribution effect can be achieved.

When we set up a network environment, we must do more tests to find out what we did not notice, or when the network load is light, test several router parameters of the network, and use these parameters to calculate the overhead of each route at that time, and then evaluate whether the configured measurement indicators are reasonable.