Spark IOProvider Invalid argument error when >10 neighbors

[guodong]

Issue Description

I test the main branch of OpenR with the topo where a router has 12 neighbor OpenR routers, but the log shows errors for Spark:

E0327 03:06:50.315670 155542 Spark.cpp:1055] [SparkHeartbeatMsg] Failed sending pkt towards: ff02::1 over: rsw_0_0 due to error: Invalid argument

The log reports that both SparkHelloMsg and HeartBeatMsg failed to be sent.

However, when the number of neighbors is small (i.e., 4 neighbors), there are no such errors.

Some of the logs

E0327 03:17:15.899060 164757 Spark.cpp:2044] [SparkHelloMsg] Failed sending pkt towards: ff02::1 over: rsw_0_4 due to error: Invalid argument
E0327 03:17:15.899388 164757 Spark.cpp:2044] [SparkHelloMsg] Failed sending pkt towards: ff02::1 over: rsw_0_2 due to error: Invalid argument
E0327 03:17:15.899632 164757 Spark.cpp:2044] [SparkHelloMsg] Failed sending pkt towards: ff02::1 over: ssw_0_4 due to error: Invalid argument
E0327 03:17:15.899874 164757 Spark.cpp:2044] [SparkHelloMsg] Failed sending pkt towards: ff02::1 over: rsw_0_0 due to error: Invalid argument
E0327 03:17:15.900093 164757 Spark.cpp:2044] [SparkHelloMsg] Failed sending pkt towards: ff02::1 over: ssw_0_2 due to error: Invalid argument
E0327 03:17:15.900227 164757 Spark.cpp:2044] [SparkHelloMsg] Failed sending pkt towards: ff02::1 over: ssw_0_1 due to error: Invalid argument
E0327 03:17:15.900311 164757 Spark.cpp:2044] [SparkHelloMsg] Failed sending pkt towards: ff02::1 over: rsw_0_3 due to error: Invalid argument
E0327 03:17:15.900405 164757 Spark.cpp:2044] [SparkHelloMsg] Failed sending pkt towards: ff02::1 over: ssw_0_0 due to error: Invalid argument
E0327 03:17:15.900459 164757 Spark.cpp:2044] [SparkHelloMsg] Failed sending pkt towards: ff02::1 over: ssw_0_3 due to error: Invalid argument
E0327 03:17:15.900524 164757 Spark.cpp:2044] [SparkHelloMsg] Failed sending pkt towards: ff02::1 over: rsw_0_5 due to error: Invalid argument
E0327 03:17:15.900597 164757 Spark.cpp:2044] [SparkHelloMsg] Failed sending pkt towards: ff02::1 over: ssw_0_5 due to error: Invalid argument
E0327 03:17:15.900686 164757 Spark.cpp:2044] [SparkHelloMsg] Failed sending pkt towards: ff02::1 over: rsw_0_1 due to error: Invalid argument
...
...
E0327 03:17:16.691227 164757 Spark.cpp:1056] [SparkHeartbeatMsg] Failed sending pkt towards: ff02::1 over: ssw_0_0 due to error: Invalid argument
E0327 03:17:16.692314 164757 Spark.cpp:1056] [SparkHeartbeatMsg] Failed sending pkt towards: ff02::1 over: rsw_0_4 due to error: Invalid argument
E0327 03:17:16.693417 164757 Spark.cpp:1056] [SparkHeartbeatMsg] Failed sending pkt towards: ff02::1 over: rsw_0_0 due to error: Invalid argument
E0327 03:17:16.694502 164757 Spark.cpp:1056] [SparkHeartbeatMsg] Failed sending pkt towards: ff02::1 over: ssw_0_5 due to error: Invalid argument
E0327 03:17:16.695578 164757 Spark.cpp:1056] [SparkHeartbeatMsg] Failed sending pkt towards: ff02::1 over: rsw_0_3 due to error: Invalid argument
E0327 03:17:16.696640 164757 Spark.cpp:1056] [SparkHeartbeatMsg] Failed sending pkt towards: ff02::1 over: ssw_0_2 due to error: Invalid argument
E0327 03:17:16.697663 164757 Spark.cpp:1056] [SparkHeartbeatMsg] Failed sending pkt towards: ff02::1 over: rsw_0_1 due to error: Invalid argument
E0327 03:17:16.698629 164757 Spark.cpp:1056] [SparkHeartbeatMsg] Failed sending pkt towards: ff02::1 over: rsw_0_5 due to error: Invalid argument
E0327 03:17:16.699409 164757 Spark.cpp:1056] [SparkHeartbeatMsg] Failed sending pkt towards: ff02::1 over: ssw_0_4 due to error: Invalid argument
E0327 03:17:16.700145 164757 Spark.cpp:1056] [SparkHeartbeatMsg] Failed sending pkt towards: ff02::1 over: ssw_0_1 due to error: Invalid argument
E0327 03:17:16.700853 164757 Spark.cpp:1056] [SparkHeartbeatMsg] Failed sending pkt towards: ff02::1 over: ssw_0_3 due to error: Invalid argument
E0327 03:17:16.701540 164757 Spark.cpp:1056] [SparkHeartbeatMsg] Failed sending pkt towards: ff02::1 over: rsw_0_2 due to error: Invalid argument