OnixS C++ CME Market Data Handler  5.4.0
API documentation
Connectivity Troubleshooting

Issues Related to Receiving Multicast Data

In most cases, the absence of multicast data is caused by network-related configuration issues described below.

Firewall Blocks Program and GettingStarted Sample

Usually, updating firewall rules or simply turning it off solves the issue.

Note
Disabling firewall explicitly may be dangerous. Consult your network and system administrator before turning the firewall off.

Linux-like Operating System Turns on Reverse Path Filtering on Network Interfaces

Disabling reverse path filtering by updating system control parameters usually resolves the issue.

System control parameters (/etc/sysctl.conf) affecting reverse path filtering:

Parameter Description
net.ipv4.conf.default.rp_filter Defines default policy.
net.ipv4.conf. NetworkInterface .rp_filter Defines policy for a NetworkInterface network interface.

To determine the current status of reverse path filtering run the command below:

1 sysctl -a | grep rp_filter

To disable reverse path filtering from console run following command:

1 echo 0 > /proc/sys/net/ipv4/conf/<NetworkInterface>/rp_filter

Explicit Network Interface Must Be Specified

GettingStarted sample program configures the Handler to listen to market data on all network interfaces on Windows and Linux. If network configuration supposes specifying exact network interface (like 'eth0' on Linux) for market data listening, then OnixS::CME::MDH::FeedSettings::networkInterface parameter value must be updated accordingly.

More Information

More information can be found in our Lost multicast packets troubleshooting guide.