# ndd -get /dev/ip ip_forward_src_routedif the value is 1 then the machine will forward source routed frames, if 0 it wont.
ndd -set /dev/ip ip_forward_src_routed 0docs.sun.com has a Solaris Tunable Paramters Refrence manual which is pretty handy take a look at that.
Some other useful info:
# ndd /dev/ip ?
This is covered in detail in the BluePrint OnLine article 'Solaris OE
Network Settings for Security: updated for Solaris 8 OE' pages 15 and
16. The article is available at:
There is a script (nddconfig) available from http://sun.com/security/blueprints which can be used to automate setting this option and others