Troubleshooting the new network segment slow internet

Failure phenomena:

Customer response in the internal new addition of a network segment, the network segment Internet speed is very slow, open the Web page takes a long time!

Customer network environment:

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Troubleshooting Procedures :

After understanding the customer in D-sw-a added a new network segment, the following PC Internet speed is very slow, in the customer site testing, and replaced the original network segment, the Internet speed immediately return to normal. It's not science!

Log on to d-sw-a to check the switch configuration and find that there is nothing wrong with the new network segment OSPF declared normal. Log on to core-a, use the SH IP route to discover that Core-a can learn the route of a new network segment, check the core-b and the firewall in turn, and discover that there are no problems with routing.

Check the user network environment again, the user has two exits, one is the operator 1G exit, the other is the internal network. Two links do load balancing, usually can surf the internet!

Since the routing is not a problem, then the detection from the export!

The gateway of the operator's gateway and the Internal network (the interface address of Router a) are ping on the PC, and the discovery is all through. But where is the problem?

Testing on the PC again, using the TRACERT command for route tracking, after many tests finally found that when using a new network segment, if the packet Walk 1G exit, then the Internet is no problem. If the packet goes inside the network, it will be there when it arrives at Router B.

It appears that the problem may be on router B, contacting the relevant person, logging on to Router B to check that there is no new network segment callback on Router B. Manually specify a callback route and test again to find that the network is healthy.

Summarize:

The problem eventually occurs in the routing, but think, if there is only one exit, then the problem may be very good judgment, it is because of the current user's network environment, only to create a user can, but the internet slow problem. Users on the firewall to do load balancing, firewalls will determine at a certain time to arrive at the destination of the path which is optimal, that is, in the first minute, the firewall may be judged to walk 1G exit is the fastest, but the next minute, the firewall may be judged to walk the internal network is the fastest! So finally there is the user reflects the situation ...

This fault has been resolved ...

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Troubleshooting the new network segment slow internet