What does it mean when the edns0 response to a dig says the overall packet size will be one value but the message size reported is different. For example in this reponse the OPT PSEUDOSECTION says udp: 4096 but at the end it says MSG SIZE rcvd: 275.
$ dig www.google.com ; <<>> DiG 9.9.3-P2-gci-9.9.3-P2-1.P2.gci.el6 <<>> www.google.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18023 ;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 4, ADDITIONAL: 5 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;www.google.com. IN A ;; ANSWER SECTION: www.google.com. 113 IN A 74.125.131.147 www.google.com. 113 IN A 74.125.131.103 www.google.com. 113 IN A 74.125.131.99 www.google.com. 113 IN A 74.125.131.105 www.google.com. 113 IN A 74.125.131.104 www.google.com. 113 IN A 74.125.131.106 ;; AUTHORITY SECTION: google.com. 95419 IN NS ns4.google.com. google.com. 95419 IN NS ns3.google.com. google.com. 95419 IN NS ns2.google.com. google.com. 95419 IN NS ns1.google.com. ;; ADDITIONAL SECTION: ns1.google.com. 95419 IN A 216.239.32.10 ns2.google.com. 95419 IN A 216.239.34.10 ns3.google.com. 95419 IN A 216.239.36.10 ns4.google.com. 95419 IN A 216.239.38.10 ;; Query time: 0 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Wed Sep 11 11:56:32 EDT 2013 ;; MSG SIZE rcvd: 275 I want to know because I have been asked what the impact to DNS in our environment would be if they dropped udp fragments at the border. It seems to me I would have to configure our name servers to drop back to tcp when a packet is over 1500. I'm trying to understand just how much that would impact the servers. Thanks, Maria _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
