I guess I may have answered this question for myself. At least I can simulate it with ncat. Note that I have two ncat sessions open to the same remote server using the same source port, but with different source IPs.
[root@testserver ~]# netstat -antp|grep ncat tcp 0 0 192.168.11.215:3456 192.168.10.59:9000 ESTABLISHED 60946/ncat tcp 0 0 192.168.10.58:3456 192.168.10.59:9000 ESTABLISHED 60920/ncat Is there any reason why tomcat should not be expected to work the same way? And when I say tomcat, I really mean libraries like the mysql odbc connector that tomcat uses. > -----Original Message----- > From: Eric Robinson <eric.robin...@psmnv.com> > Sent: Thursday, June 24, 2021 3:19 PM > To: Tomcat Users List <users@tomcat.apache.org> > Subject: Re-Use TCP Source Ports if the Socket is Unique? > > Two quick questions. > > Question 1: > > When tomcat creates a TCP connection to a remote server (for example, a > back-end database) tomcat is acting as the TCP client in that case. Does it > use > the IP it is listening on as the source IP for its outbound client connection? > > For example, Server1 has three IPs: 10.0.0.1 (primary), and two additional > IPs, 10.0.0.2 and 10.0.0.3. Tomcat is listening on 10.0.0.2. It receives a > request > that requires it to connect to a database server. When it creates a TCP > connection the database server, which IP does it use as the source address? > > Question 2: > > Suppose you have two instances of tomcat on the same server. TomcatA is > listening on 10.0.0.2 and TomcatB on 10.0.0.3. First, TomcatA establishes a > connection to a remote server from its source IP 10.0.0.2, source port 3456. > Can TomcatB, which is listening on a different IP, also establish a connection > to the remote database server using the same source port 3456, given that > the sockets is unique (different source IP)? > > -Eric > > > > > > > Disclaimer : This email and any files transmitted with it are confidential and > intended solely for intended recipients. If you are not the named addressee > you should not disseminate, distribute, copy or alter this email. Any views or > opinions presented in this email are solely those of the author and might not > represent those of Physician Select Management. Warning: Although > Physician Select Management has taken reasonable precautions to ensure > no viruses are present in this email, the company cannot accept responsibility > for any loss or damage arising from the use of this email or attachments. Disclaimer : This email and any files transmitted with it are confidential and intended solely for intended recipients. If you are not the named addressee you should not disseminate, distribute, copy or alter this email. Any views or opinions presented in this email are solely those of the author and might not represent those of Physician Select Management. Warning: Although Physician Select Management has taken reasonable precautions to ensure no viruses are present in this email, the company cannot accept responsibility for any loss or damage arising from the use of this email or attachments. --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
