On a RH5885 V3 running SUSE 11, a SAP HANA database has been installed. After Yast2 is used to add the route information 10.0.8.0/24, the IP gateway whose destination address is 10.0.8.X is changed to 10.80.3.254 (the route traverses the bond0 port whose IP address is 10.80.3.2). However, the route does not take effect after the setting, as shown in the following figure.
(1) Yast2 is used to add the IP gateway 10.80.3.354 for the route 10.0.8.0/24.
Figure 1 Adding a route using YAST2
(2) The route command is run to check the routing table. No information about the new route 10.0.8.0/24 is found.
Figure 2 Querying the routing table using the route command
The ifstatus command is run to view the detailed information about the bond0 port. Information about routes in the network segment is not found in the list of activated routes.
If YAST2 is used to add a route, the system does not display any success or error message, and you cannot determine whether the operation is successful or not. In this case, query the system route configuration table to check whether the route has been added to the system.
VLBHANA002:~ # cat /etc/sysconfig/network/routes
10.80.4.0 10.80.4.254 255.255.255.0 bond1
10.80.5.0 10.80.5.254 255.255.255.0 eth6
10.80.6.0 10.80.4.254 255.255.255.0 eth4
172.17.0.0 10.80.3.254 255.255.0.0 bond0
192.168.2.0 10.80.3.254 255.255.255.0 bond0
10.80.3.0 10.80.3.254 255.255.255.0 bond0
10.0.8.0 10.80.3.254 255.255.255.0 bond0
default 10.80.2.254 - -
It is suspected that the route does not take effect because the 10.0.8.X network segment is unreachable. However, the 10.0.8.X network segment is proven reachable from other devices on the same network. In addition, whether the network segment is reachable is not a determining factor for the result of adding a route.
Tests on the mirroring environment show that that the sequence of adding routes can determine whether a route will take effect. For example, if route 10.0.80.0 10.80.3.254 255.255.255.0 bond0 is the last route being added, it will not be active. This complies with the symptom on the live network.
If 10.0.80.0 10.80.3.254 255.255.255.0 bond0 is moved before the direct route 10.80.3.0, the route is active.
The following description is found in SUSE-specific cases:
Configuring a direct route and then adding another route does not take effect (conflict)
Based on the preceding analysis, if a route is added after a direct route is configured, this route does not take effect. The current IP address of the NIC is 10.80.3.2. This is a direct route and does not require forwarding. If the route 10.80.3.254 is added, then the route 10.0.8.0 10.80.3.254 will not take effect. In this case, you need to delete the route 10.80.3.0 10.80.3.254.
Deleting a route using YAST2 or restarting the network service will cause network interruption for a short period of time. Ensure that services are not affected when performing this operation.