DB2 - Problem description
Problem IT18608 | Status: Closed |
ON A NAT ENVIRONMENT WITH THE REGISTRY VARIABLE DB2_HADR_NO_IP_CHECK TURNED ON, HAS ISSUES WITH MULTIPLE HADR STANDBYS. | |
product: | |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 | |
Problem description: | |
Currently DB2 does not support DB2_HADR_NO_IP_CHECK with multiple standbys. It would require a change to the DB2 product. The principle standby has address X, but it sits behind a router which does NAT to translate address X to Y. The standby makes a connection to the primary. This forms a TCP/IP connection via a 3-way TCP handshake. During this handshake and all subsequent messages, the principle standby constructs a network packet with TCP and IP headers. These headers contain the address X as the source address. When the packet goes through the router, source address X is changed to Y in the TCP/IP header. The primary receives these packets with a TCP/IP header indicating that it was sent by source address Y. When the primary responds, it creates a TCP/IP header indicating Y is the destination address. When this reaches the router, it changes the destination address from Y to X and forwards it to the standby. After the TCP/IP connection forms, the primary prints the address of the connection. This comes from the TCP/IP header, so it is address Y. Later on, the primary receives the full handshake message. This looks at the source address in the handshake message, which is address X. Therefore the addresses do not match. The solution requires an update to the product by IBM and a special configuration by the customer. When a remote host is behind a NAT, then the local host should be set up with the following configuration ... - Set DB2_HADR_NO_IP_CHECK to true - Configure HADR_TARGET_LIST using the address of the NAT router. - Configure HADR_TARGET_LIST using the port specified by remote host's HADR_LOCAL_SVC. - Configure port forwarding on the NAT router so that any message sent to the router's HADR_LOCAL_SVC will be forwarded to HADR_LOCAL_ADDR. | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * All DB2 LUW Users, using HADR in NAT environment * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 LUW 10.5 Fix Pack 9 or later * **************************************************************** | |
Local Fix: | |
Solution | |
First fixed in DB2 LUW 10.5 Fix Pack 9 | |
Workaround | |
not known / see Local fix | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 29.12.2016 27.09.2017 27.09.2017 |
Problem solved at the following versions (IBM BugInfos) | |
9.0. | |
Problem solved according to the fixlist(s) of the following version(s) |