Connect and debug E500 FW to the peer device, but find the port cannot up all the time
1, check the physical link and pigtail, and no problem
2, all 2 devices have this phenomenon, can eliminate hardware damage problem at the same time.
3, make sure the peer end device is normal
4, check the configuration find that there is a link - group configuration under the port.
Link - group characteristic, is mainly used in firewall transparent mode, uplink break but downlink can not apperceive, and messages send to the firewall but discarded.
Combined with the characteristic to analyze, because the device is still in debugging stage. Ascending devices have not connected, ascending port is down, because having link- group characteristic, the ascending port down, the descending port will set down too(no matter downlink is normal or not). Lead to descending connected port can not up
Temporary delete this configuration and interconnect, port normally up.
1, link problem
2, port, board and module hardware problem
3, the peer end device problem
4, characteristic problem
This case is caused by the fourth reason
To understand characteristic firstly, which easy to the problem analysis and positioning.