Help , a problem about the tcp client under dynamic DNS

[fengxi]

I use the wip tcp client function , connect to remote PC running a TCP server program. The remote PC have public dynamic IP address. So I use a Dynamic DNS for it.

wip_TCPClientCreateOpts( myDynaDomain.com, 1024, myTcpHandler, NULL, WIP_COPT_KEEPALIVE, 10, WIP_COPT_END);

the module work fine, but have some problem in below even:

1 When the network drop ( for example , the remote PC network cable been pull ) , no any error showed by the module.

2 When the remote PC IP address is changed, the module can’t reconnect to the new IP by the dynamic domain. until reboot the module.

Maybe I use the function in wrong way, please give me some advice. thanks.

[lqmanhkeem]

When the network drop ( for example , the remote PC network cable been pull ) , no any error showed by the module.

Your myTcpHandler should raise event WIP_CEV_PEER_CLOSE, if not you must check return value from your function.

wip_TCPClientCreateOpts( myDynaDomain.com, 1024, myTcpHandler, NULL, WIP_COPT_KEEPALIVE, 10, WIP_COPT_END);

When the remote PC IP address is changed, the module can’t reconnect to the new IP by the dynamic domain. until reboot the module.

I’m not sure with this case, MAYBE it caching DNS answer before, I don’t know

[awneil]

@lqmanhkeem

MAYBE it caching DNS answer before, I don’t know

That seems highly probable…

[fengxi]

@lqmanhkeem

When the network drop ( for example , the remote PC network cable been pull ) , no any error showed by the module.

Your myTcpHandler should raise event WIP_CEV_PEER_CLOSE, if not you must check return value from your function.

wip_TCPClientCreateOpts( myDynaDomain.com, 1024, myTcpHandler, NULL, WIP_COPT_KEEPALIVE, 10, WIP_COPT_END);

When the remote PC IP address is changed, the module can’t reconnect to the new IP by the dynamic domain. until reboot the module.

I’m not sure with this case, MAYBE it caching DNS answer before, I don’t know

1. The WIP_CEV_PEER_CLOSE will catch by myTcpHandler only the remote PC TCP server program regular close the connection. But when the network drop, nothing event will be catched. I think the WIP_COPT_KEEPALIVE should have some help for this case, but nothing change.

2. I think so. The DNS result might be cached by the module. Does any method to clear the cache, or setting the wip_TCPClientCreateOpts auto update the DNS again in establish the new connection?