No subject

First I got the ip from company ,which mean i can have the network 10.16.172.0
using br0 as bridge .The guest os  can have a ip 10.16.172.78 (manly set)
The error show , 10.1.1.9  was a router which don't know the ip 10.16.172.78  ?
I can't ping the guest os , but that's why i use tap mode in qemu
.Because qemu stack mode also can
connect to outside. but wasn't seen in host os .

I think don't need ask system manager to set it . Am i right ? How can
i make host ping the guest rightly ?