Steps for troubleshooting firewall problems

The first step is to test network connectivity.

1. Use ping to check the network connection

2. Check whether there is access equipment and whether it is authorized (Inode)

3, if not authorized for authentication

Step 2: Check whether the policy exists

1. Locate the fault point, www.baidu.com cannot be accessed

2. Use nslookup plus domain name resolution to resolve the IP address of the domain name

3. Use telnet to access the port. Do you want to access it?

Testing DNS server connectivity (ping)

Step 3: Check whether the strategy is effective

1, the domain name can be accessed (some pages require a specified browser)

2. If you can't access it, add a release and visit it again.

Internet interconnection entries must be released, sometimes customers cannot download files, an internal network must be released to all

Step 4: Check the upper route entries again

1. If it cannot be accessed again, inform the upper technician and check the routing path.

2. At this time, make corresponding adjustments with the opposite end technology.

Step 5: Check whether there are other safety devices in the chain.

1. Check the status table on the firewall to see if the connection is established.

2. Check whether there are high-risk ports to block events of other devices.