Anand Shankar wrote: > 1. Is it possible to have two or more different IPs assigned to the > same physical host name (DNS Record Type A)?
Yes, it is. And it is a common way to distribute traffic over multiple servers. DNS clients would normally use the different A records in a round robin manner. $ dig yahoo.com ... yahoo.com. 300 IN A 66.94.234.13 yahoo.com. 300 IN A 216.109.112.135 $ dig cnn.com ... cnn.com. 300 IN A 64.236.16.116 cnn.com. 300 IN A 64.236.24.12 cnn.com. 300 IN A 64.236.24.20 cnn.com. 300 IN A 64.236.24.28 cnn.com. 300 IN A 64.236.29.120 cnn.com. 300 IN A 64.236.16.20 cnn.com. 300 IN A 64.236.16.52 cnn.com. 300 IN A 64.236.16.84 > > 2. If yes, is it possible to assign different metric weights to > prioritise traffic to one link over the other and also to provide fail > over redundancy - ie if connectivity with one physical link breaks, > the traffic flows in through the other link? No. The IP addresses will be used in order and repeated, i.e. round-robin manner. You have to do your own backend failover. Large web providers typically have round robin IPs directing to vips which in turn distribute traffic among various actual servers. The vip does the work that you ask for. The client has no clue what your links to the internet are, or in which condition they are. If one IP doesn't work, it will try the other. > > 3. Is this facility provided by DNS Registrars/ Service Providers like > Network Solutions etc Round robin DNS is normally supported by the clients themselves. The DNS provider simply adds the A records that you ask for - you can ask for multiple A records for the same host name. That is all you need. - Sandip _______________________________________________ ilugd mailinglist -- ilugd@lists.linux-delhi.org http://frodo.hserus.net/mailman/listinfo/ilugd Archives at: http://news.gmane.org/gmane.user-groups.linux.delhi http://www.mail-archive.com/ilugd@lists.linux-delhi.org/
