[Click] XORP+Click Hotconfig

[Swati Sinha Deb]

Hi,

I am trying to implement hotswap in my xorp+click test bed. However, it is 
not functioning correctly. I would appreciate if I get some help to fix 
this issue. Here is what I am trying to do...

Network configuration
---------------------


PC 1---------ROUTER1------ROUTER2--------PC 2
            eth4  eth3   eth1  eth2

Where Router1 and Router2 are both running Xorp+click. The xorp config file 
has the following entry...

user-click {
	disable: false
	command-file: "/home/eessd/click/bin/click"
	command-extra-arguments: "-R"
	command-execute-on-startup: true
	control-address: 127.0.0.1
	control-socket-port: 13000
	startup-config-file: "/dev/null"
	user-click-config-generator-file: 
"/usr/localxorp/fea/xorp_fea_click_config"
}

Given the above all is well and I can ping PC2 from PC1 with the above 
configuration.

Now, I try to change the click configuration in ROUTER1. For doing this, I 
have a separate application which connects to port 13000 on ROUTER1 and 
invokes the relevant controlsocket server commands (writedata and write on 
hotconfig handler). The server returns a success i.e, 200 OK indicating 
that the new config has been applied correctly. However, when I try to ping 
PC2   from PC1 it starts failing.

I have compared the old and new click configuration and there is nothing 
which should prevent the ping from failing (I have changed a few parameters 
to my custom/local click elements). Is there something fundamentally 
incorrect with the above approach.

I have also tried defining my own controlsocket (port 14000) via config 
file (added a statement in /usr/localxorp/fea/xorp_fea_click_config inorder 
to do this). But I encounter the same issue. The server returns OK after 
each hotswap attempt and the ping fails.

Would be great if I get some tips on fixing the above issue. Please let me 
know if I have missed out anything which would help in this investigation.

Additionally after hotswap, a tcpdump on eth3 (Router1) indicates that the 
ping packets are not reaching eth3, I can see it on eth4. The xorp routing 
table is also fine.

Thanks
Swati