Hi folks! Ok, I'm at my wits end here and I'm hoping someone can give me some pointers in the right direction. I am running RedHat 7.2 as a PDC (Samba 2.2.1a), with Postfix for my SMTP server, and UW's Imap server for POP. I'm not running a DNS server on this machine (DNS services come from our upstream ISP). Here's what I'm observing: 1. From the local network...When I try to SSH into the linux box, connect via POP, send mail, or log into the domain, it frequently takes up at least 30 seconds to establish a connection. 2. From the outside world...When I try to SSH into the linux box, connect via POP, or send mail, its a snap (just a few seconds at most) to connect to the box. It almost seems as if something on the box is trying to do reverse dns lookups on private IPs. I've been searching in vain to try and figure out what controls this and how to either a) configure it to not do reverse dns on private ips, or b) turn off reverse dns altogether. I've searched all the specific application conf files for Postfix, Samba, SSH, etc, and can't find anything. The fact that this slowness is affecting all of these programs seems to suggest that the problem is occurring at some lower level that they all use. Unfortunately, I'm at a loss as to where to look next. On a similarly configured box, where the only difference is that Samba is not acting as a domain controller, I don't experience any slowdowns, both for internal and external access. SO...does this sound like a Samba related issue? Or do I need to look elsewhere (if so, where). tia, Christian ---------------------------------------------- Christian Cryder [christianc@atmreports.com] Internet Architect, ATMReports.com Barracuda - http://barracuda.enhydra.org ---------------------------------------------- "What a great time to be a(n employed) Geek"
You could set up an internal DNS server for your network, which is what I do. Everything inside points to that DNS server and it forwards queries it can't answer to the ISP's DNS servers. This also allows it to act as a caching server to speed up resolution for frequently accessed domains. Your other option is to make entries for all the machines in your network in the /etc/hosts file of your server. My suggestion is to set up a DNS server for your internal network. Hope this helps. At 02:02 PM 3/27/2002 -0700, Christian Cryder wrote:>Hi folks! > >Ok, I'm at my wits end here and I'm hoping someone can give me some pointers >in the right direction. I am running RedHat 7.2 as a PDC (Samba 2.2.1a), >with Postfix for my SMTP server, and UW's Imap server for POP. I'm not >running a DNS server on this machine (DNS services come from our upstream >ISP). Here's what I'm observing: > >1. From the local network...When I try to SSH into the linux box, connect >via POP, send mail, or log into the domain, it frequently takes up at least >30 seconds to establish a connection. > >2. From the outside world...When I try to SSH into the linux box, connect >via POP, or send mail, its a snap (just a few seconds at most) to connect to >the box. > >It almost seems as if something on the box is trying to do reverse dns >lookups on private IPs. I've been searching in vain to try and figure out >what controls this and how to either >a) configure it to not do reverse dns on private ips, or >b) turn off reverse dns altogether. > >I've searched all the specific application conf files for Postfix, Samba, >SSH, etc, and can't find anything. The fact that this slowness is affecting >all of these programs seems to suggest that the problem is occurring at some >lower level that they all use. Unfortunately, I'm at a loss as to where to >look next. > >On a similarly configured box, where the only difference is that Samba is >not acting as a domain controller, I don't experience any slowdowns, both >for internal and external access. SO...does this sound like a Samba related >issue? Or do I need to look elsewhere (if so, where). > >tia, >Christian >---------------------------------------------- >Christian Cryder [christianc@atmreports.com] >Internet Architect, ATMReports.com >Barracuda - http://barracuda.enhydra.org >---------------------------------------------- > "What a great time to be a(n employed) Geek" > > >-- >To unsubscribe from this list go to the following URL and read the >instructions: http://lists.samba.org/mailman/listinfo/samba-- ----------------------------------------------------------- Kourosh Ghassemieh MindWare Information Systems & Technologies 9255 Sunset Blvd, Penthouse West Hollywood CA 90069 Tel: (310) 729-1784 kourosh@atlanticpearl.com
This is not samba related questions. You can speed up reverse dns adding ip and machine name to /etc/hosts -file -- Eero ----- Original Message ----- From: "Christian Cryder" <christianc@granitepeaks.com> To: "Samba" <samba@lists.samba.org> Sent: Wednesday, March 27, 2002 11:02 PM Subject: [Samba] Reverse DNS question> Hi folks! > > Ok, I'm at my wits end here and I'm hoping someone can give me somepointers> in the right direction. I am running RedHat 7.2 as a PDC (Samba 2.2.1a), > with Postfix for my SMTP server, and UW's Imap server for POP. I'm not > running a DNS server on this machine (DNS services come from our upstream > ISP). Here's what I'm observing: > > 1. From the local network...When I try to SSH into the linux box, connect > via POP, send mail, or log into the domain, it frequently takes up atleast> 30 seconds to establish a connection. > > 2. From the outside world...When I try to SSH into the linux box, connect > via POP, or send mail, its a snap (just a few seconds at most) to connectto> the box. > > It almost seems as if something on the box is trying to do reverse dns > lookups on private IPs. I've been searching in vain to try and figure out > what controls this and how to either > a) configure it to not do reverse dns on private ips, or > b) turn off reverse dns altogether. > > I've searched all the specific application conf files for Postfix, Samba, > SSH, etc, and can't find anything. The fact that this slowness isaffecting> all of these programs seems to suggest that the problem is occurring atsome> lower level that they all use. Unfortunately, I'm at a loss as to where to > look next. > > On a similarly configured box, where the only difference is that Samba is > not acting as a domain controller, I don't experience any slowdowns, both > for internal and external access. SO...does this sound like a Sambarelated> issue? Or do I need to look elsewhere (if so, where). > > tia, > Christian > ---------------------------------------------- > Christian Cryder [christianc@atmreports.com] > Internet Architect, ATMReports.com > Barracuda - http://barracuda.enhydra.org > ---------------------------------------------- > "What a great time to be a(n employed) Geek" > > > -- > To unsubscribe from this list go to the following URL and read the > instructions: http://lists.samba.org/mailman/listinfo/samba >
This isn't really a samba issue, but congrats on having correctly diagnosed the problem yourself. With a DNS server configured in /etc/resolv.conf, your system is indeed trying to reverse lookup the IP's of your internal machines. Samba itself will do this if you have domain names in the hosts allow / hosts deny directive of smb.conf. I suspect inetd will also perform reverse lookups for services it controls. (I might be wrong there however.) The quick and dirty way to get around this is to create an entry in your /etc/hosts file for all your internal machines. Some people also set up their own DNS server instead. <shrugs>. Being a very lazy person, I just simply lists my local addresses in hosts. ____________________________________________ Mar 27 10:45pm _ ASCII ribbon campaign ( ) - against HTML email X & vcards / \ On Wed, 27 Mar 2002, Christian Cryder wrote: Hi folks! Ok, I'm at my wits end here and I'm hoping someone can give me some pointers in the right direction. I am running RedHat 7.2 as a PDC (Samba 2.2.1a), with Postfix for my SMTP server, and UW's Imap server for POP. I'm not running a DNS server on this machine (DNS services come from our upstream ISP). Here's what I'm observing: 1. From the local network...When I try to SSH into the linux box, connect via POP, send mail, or log into the domain, it frequently takes up at least 30 seconds to establish a connection. 2. From the outside world...When I try to SSH into the linux box, connect via POP, or send mail, its a snap (just a few seconds at most) to connect to the box. It almost seems as if something on the box is trying to do reverse dns lookups on private IPs. I've been searching in vain to try and figure out what controls this and how to either a) configure it to not do reverse dns on private ips, or b) turn off reverse dns altogether. I've searched all the specific application conf files for Postfix, Samba, SSH, etc, and can't find anything. The fact that this slowness is affecting all of these programs seems to suggest that the problem is occurring at some lower level that they all use. Unfortunately, I'm at a loss as to where to look next. On a similarly configured box, where the only difference is that Samba is not acting as a domain controller, I don't experience any slowdowns, both for internal and external access. SO...does this sound like a Samba related issue? Or do I need to look elsewhere (if so, where). tia, Christian ---------------------------------------------- Christian Cryder [christianc@atmreports.com] Internet Architect, ATMReports.com Barracuda - http://barracuda.enhydra.org ---------------------------------------------- "What a great time to be a(n employed) Geek" -- To unsubscribe from this list go to the following URL and read the instructions: http://lists.samba.org/mailman/listinfo/samba