Hi, I recently setup a CentOS 5 file server for a small LAN consisting of 15 Windows XP clients. The LAN is eventually expected to migrate to Linux, at least some of the client machines. The previous setup made by a local Windows-only computer firm was an unhealthy mix of static and dynamic IP addresses with conflicting adresses, etc. First thing I undertook was clean up this mess by setting up a DHCP + local cache DNS server on the Linux machine. Now the curious problem I have: IP addresses are attributed correctly, people can surf on the internet all right. But the only thing they can't seem to do is send mail with Outlook or Outlook Express. I have to revert to the ISP's DNS, but so I lose the benefit of local DNS. And I don't have the slightest clue as to why that is so. Here's my setup, maybe one of the gurus on the list has an idea: 1) /etc/dhcpd.conf (the fixed addresses are attributed because the local printer has a page counting device that works with IP adresses): --8<--------------------------------------- ddns-update-style interim; authoritative; default-lease-time 86400; max-lease-time 86400; option broadcast-address 192.168.0.255; option subnet-mask 255.255.255.0; option routers 192.168.0.1; option domain-name-servers 192.168.0.2; option domain-name "regards.arles"; subnet 192.168.0.0 netmask 255.255.255.0 { range 192.168.0.100 192.168.0.150; } host poste1 { hardware ethernet 00:26:18:B7:D6:10; fixed-address 192.168.0.101; option host-name "poste1"; } host poste2 { hardware ethernet 00:24:81:69:A3:DE; fixed-address 192.168.0.102; option host-name "poste2"; } host poste3 { hardware ethernet 00:1B:FC:6F:66:2C; fixed-address 192.168.0.103; option host-name "poste3"; } ... --8<--------------------------------------- For setting up Bind, I used a "dummy" domain name, like I usually do in LAN's. For example, my home network is "presbytere.montpezat", the local town hall's network is "mairie.montpezat". The network here is "regards.arles". ("Regards" is the name of a local association, and "Arles" is the city in South France where it's located). 2) /etc/named.conf: --8<--------------------------------------- options { directory "/var/named"; listen-on { 127.0.0.1; 192.168.0.0/24; }; }; zone "." IN { type hint; file "named.root"; }; zone "localhost" IN { type master; file "zone.localhost"; allow-update { none; }; }; zone "0.0.127.in-addr.arpa" IN { type master; file "revp.127.0.0"; allow-update { none; }; }; zone "regards.arles" IN { type master; file "zone.arles.regards"; }; zone "0.168.192.in-addr.arpa" { type master; file "revp.192.168.0"; }; --8<--------------------------------------- 3) /var/named/named.root: --8<--------------------------------------- ; <<>> DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5 <<>> ;; global options: printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 42704 ;; flags: qr rd ra; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 14 ;; QUESTION SECTION: ;. IN NS ;; ANSWER SECTION: . 106187 IN NS h.root-servers.net. . 106187 IN NS i.root-servers.net. . 106187 IN NS j.root-servers.net. . 106187 IN NS k.root-servers.net. . 106187 IN NS l.root-servers.net. . 106187 IN NS m.root-servers.net. . 106187 IN NS a.root-servers.net. . 106187 IN NS b.root-servers.net. . 106187 IN NS c.root-servers.net. . 106187 IN NS d.root-servers.net. . 106187 IN NS e.root-servers.net. . 106187 IN NS f.root-servers.net. . 106187 IN NS g.root-servers.net. ;; ADDITIONAL SECTION: a.root-servers.net. 401883 IN A 198.41.0.4 a.root-servers.net. 401883 IN AAAA 2001:503:ba3e::2:30 b.root-servers.net. 401883 IN A 192.228.79.201 c.root-servers.net. 401883 IN A 192.33.4.12 d.root-servers.net. 401883 IN A 128.8.10.90 e.root-servers.net. 401883 IN A 192.203.230.10 f.root-servers.net. 401883 IN A 192.5.5.241 f.root-servers.net. 401883 IN AAAA 2001:500:2f::f g.root-servers.net. 401883 IN A 192.112.36.4 h.root-servers.net. 401883 IN A 128.63.2.53 h.root-servers.net. 401883 IN AAAA 2001:500:1::803f:235 i.root-servers.net. 401883 IN A 192.36.148.17 j.root-servers.net. 192587 IN A 192.58.128.30 j.root-servers.net. 192587 IN AAAA 2001:503:c27::2:30 ;; Query time: 6 msec ;; SERVER: 192.168.1.252#53(192.168.1.252) ;; WHEN: Wed May 26 18:47:37 2010 ;; MSG SIZE rcvd: 500 --8<--------------------------------------- 4) /var/named/zone.localhost: --8<--------------------------------------- $TTL 1D $ORIGIN localhost. @ IN SOA @ root ( 0000002 ; Serial 8H ; Refresh 15M ; Retry 1W ; Expire 1D) ; Minimum TTL IN NS @ IN A 127.0.0.1 --8<--------------------------------------- 5) /var/named/revp.127.0.0: --8<--------------------------------------- $TTL 1D $ORIGIN 0.0.127.in-addr.arpa. @ IN SOA localhost. root.localhost. ( 0000002 ; Serial 8H ; Refresh 15M ; Retry 1W ; Expire 1D ) ; Minimum TTL IN NS localhost. 1 IN PTR localhost. --8<--------------------------------------- 6) /var/named/zone.arles.regards: --8<--------------------------------------- $ORIGIN regards.arles. $TTL 1D @ IN SOA ibmx225 hostmaster ( 0000003 ; Serial 8H ; Refresh 4H ; Retry 4W ; Expire 1D ) ; Minimum NS ibmx225 localhost A 127.0.0.1 poste1 A 192.168.0.101 poste2 A 192.168.0.102 poste3 A 192.168.0.103 poste4 A 192.168.0.104 poste5 A 192.168.0.105 poste6 A 192.168.0.106 poste7 A 192.168.0.107 poste8 A 192.168.0.108 poste9 A 192.168.0.109 poste10 A 192.168.0.110 poste11 A 192.168.0.111 poste12 A 192.168.0.112 poste13 A 192.168.0.113 poste14 A 192.168.0.114 --8<--------------------------------------- 7) /var/named/revp.192.168.0: --8<--------------------------------------- $ORIGIN 0.168.192.in-addr.arpa. $TTL 1D @ IN SOA ibmx225.regards.arles. contact.kikinovak.net ( 0000003 ; Serial 28800 ; Refresh 14400 ; Retry 2419200 ; Expire 86400 ; Minimum ) NS ibmx225.regards.arles. 101 PTR poste1.regards.arles. 102 PTR poste2.regards.arles. 103 PTR poste3.regards.arles. 104 PTR poste4.regards.arles. 105 PTR poste5.regards.arles. 106 PTR poste6.regards.arles. 107 PTR poste7.regards.arles. 108 PTR poste8.regards.arles. 109 PTR poste9.regards.arles. 110 PTR poste10.regards.arles. 111 PTR poste11.regards.arles. 112 PTR poste12.regards.arles. 113 PTR poste13.regards.arles. 114 PTR poste14.regards.arles. --8<--------------------------------------- Any suggestions? cheers from the sunny South of France, Niki