Application Delivery (ADX)

Reply
New Contributor
Posts: 2
Registered: ‎09-10-2015

Config to load-balance with NAT using distant real servers?

[ Edited ]

I am trying to use an ADX to stand up a VIP that will proxy DNS requests via NAT to servers which are several hops away from the ADX, using NAT so that the DNS requests appear to the servers to be coming from the Brocade virtual server IP, and queries will appear to clients as being resolved by the VIP IP.

 

Example:

 

 

real server dns-server-1 10.0.0.1 
 source-nat
 no-l3-check
 port dns
real server dns-server-1 10.0.0.2
 source-nat
 no-l3-check
 port-dns
virtual server dns-vip 192.168.0.2
 next-hop 192.168.0.1
 next-hop-allow-fallback-to-default-gateway
 predictor round-robin
 port dns
 bind dns dns-server-1 dns dns-server-2 dns

However, show server bind shows real servers dns-server-1 and -2 as Failed, and the VIP does not respond to DNS queries.

 

dns -----> + dns-server-1: 10.0.0.1, dns (Failed)
           + dns-server-2: 10.0.0.2, dns (Failed)

 

 

The ADX can ping the real server IPs (10.0.0.1 and .2) without issue. What am I missing?

 

 

New Contributor
Posts: 2
Registered: ‎09-10-2015

Re: Config to load-balance with NAT using distant real servers?

Figured it out. "server real" servers in the Brocade are health-checked via ARP, which of course fails for hosts not on the local subnet. Use "server remote-name" instead.

 

 

real remote-name dns-server-1 10.0.0.1 
 source-nat
 port dns
real remote-name dns-server-1 10.0.0.2
 source-nat
 port-dns
virtual server dns-vip 192.168.0.2
 predictor round-robin
 port dns
 bind dns dns-server-1 dns dns-server-2 dns

 

Join the Community

Get quick and easy access to valuable resource designed to help you manage your Brocade Network.

Download FREE NVMe eBook