[j-nsp] is icmp unreachable generation rate-limited ?

[Alexandre Snarskii]

Hi!

Some traceroute through our network: 

                           Matt's traceroute  [v0.54]
                                                       Wed Sep 15 11:03:06 2004
Keys:  D - Display mode    R - Restart statistics    Q - Quit
                                           Packets               Pings
Hostname                                %Loss  Rcv  Snt  Last Best  Avg  Worst
 1. 192.168.10.9                           0%   17   17     0    0    0      1
 2. XX.YYY.255.34                          0%   17   17     0    0    0      0
 3. XX.YYY.255.97                          0%   17   17     1    0    4     71
 4. XX.YYY.255.1                          44%    9   17     0    0    0      0
 5. XX.YYY.2.1                             0%   17   17     0    0    0      0
 6. XX.YYY.0.130                           0%   17   17    47   47   47     48
 7. XX.YYY.0.114                           0%   17   17   152  152  152    152

At the hop 4 (Juniper M10, JUNOS 6.1R2.2) traceroute shows us a 
packet loss. But that is not a packet loss really - we were not get
0% of packet loss on next hops if it is. 

My only idea is that juniper generates not more than some limited number
of icmp unreachable packets per some interval, so, application not sees 
replies and reports that as packet loss. 

Is that true ? And, if so: are there any tunable which i can modify 
in order to increase the number ? 

Or we should just upgrade our ancient junos version ? 

PS: 'show pfe statistics ip icmp' shows huge amount of 'throttled icmps', 
is that a counter of suppressed icmps ?