Bellow is my network diagram
(a) one Load Balancer router, where 2 isp is connected.
(b) one SBS 2003 Server which is working as Dns server and in Dns management, i am using dns forwarder IP for 2 isp
order : isp 1 : xx.xx.xx.xx , yy.yy.yy.yy
isp2 : zz.zz.zz.zz
When i turned on both Isp :
User can brose properly. without any issue. from trafiq log i can see, users request is going through both isp1 and isp2 router
now if i turned off ISP1 router, so every trafiq is going through via isp2 router
but browsing is tooo slow ... . There is not any ping time out. if i connect a pc directly to isp router , it can browse without any problem, but from inside of network its slow.
so what i am suspecting is :
Since i put 3 dns server address in dns forwarder ( xx and yy is the isp1, and zz.zz.zz.zz is isp2)
now when i am turning off isp1 router, there is a dns query delay ......
but when i am turning on isp1 router, since their ip address in first order , the dns query is quick.
can it be reason ??
here : SBS server can ping zz.zz.zz.zz without any problem .