[Xorp-users] Xorp debug messages

[Pavlin Radoslavov]

> I'm currently testing my Click router multicast elements against Xorp.
> 
> What is the easiest way to make Xorp print information about the PIM 
> messages it received? Is there a way to enable Debug output for PIM only?

Add the following to your XORP configuration:

protocols {
    pimsm4 {
        ...
        traceoptions {
            flag all {
                disable: false
            }
        }
    }
}

In addition, you could add the following to the top of
pim/pim_node.cc and recompile:

#define DEBUG_LOGGING
#define DEBUG_PRINT_FUNCTION_NAME

With the latter solution PIM will print "Received message from ..."
for any message received from the MFEA.
    
> My PIM Hello messages have the following format (captured with 
> tethereal). I do not see the point why Xorp's PIM does not recognise them:
> 
> -----------------
> Capturing on eth3
> Frame 1 (72 bytes on wire, 72 bytes captured)
>     Arrival Time: Mar  1, 2006 13:05:56.263655000
>     Time delta from previous packet: 0.000000000 seconds
>     Time since reference or first frame: 0.000000000 seconds
>     Frame Number: 1
>     Packet Length: 72 bytes
>     Capture Length: 72 bytes
>     Protocols in frame: eth:ip:pim
> Ethernet II, Src: Intel_08:f0:a8 (00:04:23:08:f0:a8), Dst: 
> 01:00:5e:00:00:0d (01:00:5e:00:00:0d)
>     Destination: 01:00:5e:00:00:0d (01:00:5e:00:00:0d)
>     Source: Intel_08:f0:a8 (00:04:23:08:f0:a8)
>     Type: IP (0x0800)
> Internet Protocol, Src: 172.20.12.1 (172.20.12.1), Dst: 224.0.0.13 
> (224.0.0.13)
>     Version: 4
>     Header length: 24 bytes
>     Differentiated Services Field: 0xc0 (DSCP 0x30: Class Selector 6; 
> ECN: 0x00)
>         1100 00.. = Differentiated Services Codepoint: Class Selector 6 
> (0x30)
>         .... ..0. = ECN-Capable Transport (ECT): 0
>         .... ...0 = ECN-CE: 0
>     Total Length: 58
>     Identification: 0xf45f (62559)
>     Flags: 0x00
>         0... = Reserved bit: Not set
>         .0.. = Don't fragment: Not set
>         ..0. = More fragments: Not set
>     Fragment offset: 0
>     Time to live: 1
>     Protocol: PIM (0x67)
>     Header checksum: 0x9716 [correct]
>         Good: True
>         Bad : False
>     Source: 172.20.12.1 (172.20.12.1)
>     Destination: 224.0.0.13 (224.0.0.13)
>     Options: (4 bytes)
>         Router Alert: Every router examines packet
> Protocol Independent Multicast
>     Version: 2
>     Type: Hello (0)
>     Checksum: 0x8447 [correct]
>     PIM parameters
>         Holdtime (1): 105s
>         LAN Prune Delay (2)
>             T bit is not set
>             LAN Delay: 500ms
>             Override Interval: 2500ms
>         DR Priority (19): 2
>         Generation ID (20): 1331494912
> ------------------

There is nothing unusual I can see about the above message, so the
starting point would be to see whether the PIM-SM module receives it
at all. If not, then try to find whether the MFEA receives it.

In general, if you want to print something for debug purpose inside
the PIM-SM module or MFEA, use the XLOG_* facility (recommended) or
fprintf(stderr), but don't use printf() or fprintf(stdout).

Pavlin