Forum Discussion
CirrusSource Port Preserve in a Virtual Server
In a virtual server in the Configuration section we select the option in Source Port as "Preserve". If a client 1.2.3.4:1111 connects to the BIGIP and the Self IP is already using that particular port 1111 so what port will the Self IP use to communicate with the Pool Members?
4 Replies
Martijn_144688Cirrostratus
Hi,
Are you using SNAT? Is you are using SNAT, the client session is NATed behind this SNAT address, so the self IP can use the same port 1111 because this is a different IP/port combination.
If you are not using SNAT but the server side connection uses the IP address of the egress interface, I think the F5 attemps to preserve the source port, but selects a different port if that source port is in use. See:
K13433: Configuring source port preservation for SNATs
Preserve Specifies that the system attempts to preserve the value configured for the source port unless the source port from a particular SNAT is already in use, in which case the system uses a different port. Preserve is the default behavior.
Regards, Martijn.
Aditya_MehraHey Martijn, We have configured Source Address Translation as Auto Map and VLAN and Tunnel Traffic is are VLANs and tunnels.
Regards, Aditya
- MvdG
Hi,
Are you using SNAT? Is you are using SNAT, the client session is NATed behind this SNAT address, so the self IP can use the same port 1111 because this is a different IP/port combination.
If you are not using SNAT but the server side connection uses the IP address of the egress interface, I think the F5 attemps to preserve the source port, but selects a different port if that source port is in use. See:
K13433: Configuring source port preservation for SNATs
Preserve Specifies that the system attempts to preserve the value configured for the source port unless the source port from a particular SNAT is already in use, in which case the system uses a different port. Preserve is the default behavior.
Regards, Martijn.
- Aditya_Mehra
Hey Martijn, We have configured Source Address Translation as Auto Map and VLAN and Tunnel Traffic is are VLANs and tunnels.
Regards, Aditya
