# Prbolem about IP/MAC address of SiTCP ## Background * SiTCP Default IP address: 192.168.10.16 * Our Switch: Zyxel, HP ...etc. general(common) 1Gbps Switch * New Switches, we bought after 2012 ## Test with `ping` and `arp` ![](https://i.imgur.com/VKKPTik.png) * `ping`: No response * `arp -a`: Found IP address, but its MAC address shows `<incomplete>`???? ## When I change switch with old one Old Switch(100M/10M) ![](https://i.imgur.com/VzVzhV6.png) Connect to board ![](https://i.imgur.com/d20Evlr.png) * `ping`: OK * ![](https://i.imgur.com/7o1RncZ.png) * `rbcp` Write Byte to address: OK * ![](https://i.imgur.com/rfQ4WEC.png) * `arp -a`: MAC address appeared??????????? * ![](https://i.imgur.com/zDuuIF7.png) That's too strange! ## Summery ![](https://i.imgur.com/aHJyjGZ.png) ###### tags: `TestReport` `DeWei`