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I have a SSL-Certificate by COMODO for Now I have 3 role-based servers with 3 different IP's (web/smtp/pop3) Can I use the same SSL-Certificate for 3 different services on 3 different IP's? Thx

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Problem here would be that you cant have one name to resolve to 3 different IPs

Unless you have wildcard certificate for * your certificate for will be working properly on just one IP.

When you want to access, DNS will tell you one IP, or if you put moe than 1 entry for that name you cant be sure which answer you will get by round-robin.

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I want to access different services (ports!) imap, smtp, pop3 - I dont want to host same webserver with the same certificate. – Phoibe Feb 17 '11 at 18:47
I understand you, but what I'm telling you is say ip for ; ; ; and now you put same ssl certificate for imap/smtp/www unless it's * certificate you will get errors because FQDN does not match CN (canonical name) in certificate. – Hrvoje Špoljar Feb 17 '11 at 18:53

Yes you can use the certificate for multiple IP's / services on a server, SSL certificates are bound by a "CommonName", which is the hostname for HTTP.

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I use Debian. Where do I set the CommonName? **which is the hostname for HTTP". I have DNS pointing http to ip 1, smpt is ip 2 and pop3 is ip 3. – Phoibe Feb 17 '11 at 17:51 is the CommonName in your case. You cannot set the CommonName yourself. When you request a SSL certificate at Comodo, you'll be asked for the domain name, which is the CommonName. Are you having problems with adding the SSL cert to your web/smtp/pop3 server? – Lekensteyn Feb 17 '11 at 17:58
No I try to understand how to solve that technically. I have my CommonName = - now I want to install this certificate on a server which handles pop3 - ip - the dns entry for www is and for smtp is - is it possible to use one certificate with those 3 servers? (no wildcard cert) – Phoibe Feb 17 '11 at 18:49
@Phoibe: The IP has nothing to do with it. The client will connect to "" and look at the cert that says "" and say "this is wrong" because ""!="". Same with "" and "" – DerfK Feb 17 '11 at 18:52
@Phoibe, DerfK explained it all. It's not uncommon that SSL certs are shared among multiple machines (with different IP addresses). – Lekensteyn Feb 17 '11 at 18:59

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