HOSTS
To use this feature, you should add aliases in your hosts table (the file /etc/hosts on Unix systems) that combine two host names with a hyphen between them. Such aliases are taken as hints that these are the best interfaces to use between the two machines. The first part of a hyphenated name should be the machine that the interface is on; the second part should be the machine that the port connects to.
For instance, consider the following /etc/hosts entries from one of our lab machines:
16.126.64.156 imfine.mko.dec.com imfine 16.126.224.58 tlase1.mko.dec.com tlase1 10.1.64.156 imfine-fta1 imfine-tlase1 10.1.224.58 tlase1-fta1 tlase1-imfine 10.3.64.156 imfine-fta3 10.3.224.58 tlase1-fta3These two machines each have an Ethernet interface with a network 16.126 address, and two FDDI interfaces that are configured for networks 10.1 and 10.3. There are two special aliases:
When told to use TCP or FTP between these two machines, cscp will notice these entries, and will use the FDDI interface rather than the Ethernet.
This feature is controlled by the CS_HOST_PAIR environment variable, which is 0 (disabled) by default. If you want either cscp and csfd to do the paired-host lookup, you must set CS_HOST_PAIR to 1, either in the environment or in the appropriate config file. The reason this feature is disabled by default is: If the paired hostname entries don't exist, the nameservers may take a very long time (sometimes minutes) to time out, and you'll have this delay for every use of cscp.
In most cases, even if the paired hostnames exist in /etc/hosts (and the /etc/svcorder file has "local" first), it's still best not to let the lookup be done by cscp. The reason is that it's usually better (i.e., less prone to unexplained delays) if the lookup is done at the highest level, and the IP address passed to cscp. This gives you direct control over when the lookup happens, and you can debug the lookup in your own logfile or dbx session rather than in cscp's.