[ns] Installation problems with ns-2.33

[Siraj Shaikh]

2008/9/10 Mayur <mayur at ee.iitd.ac.in>:
> Siraj Shaikh wrote:
>>
>> 2008/9/10 Siraj Shaikh <siraj.shaikh at gmail.com>:
>>
>>>
>>> 2008/9/4 Tom Henderson <tomh at tomh.org>:
>>>
>>>>
>>>> Siraj Shaikh wrote:
>>>>
>>>>>
>>>>> I installed ns-2.33 on my machine (Ubuntu). Followed the intstructions
>>>>> on here:
>>>>> http://nsnam.isi.edu/nsnam/index.php/Installing_ns2.31_on_Ubuntu7.04
>>>>>
>>>>> Everything worked fine and as expected. No errors encountered.
>>>>>
>>>>> I the validation set up and even the path/environment variables. Have
>>>>> checked the paths since then and they are all fine.
>>>>>
>>>>> The problem: for any file xxx.tcl (in the right folder) every time I
>>>>> type
>>>>>
>>>>> $ ns xxx.tcl
>>>>>
>>>>> I get
>>>>>
>>>>> $ xxx.tcl does not exist, try again
>>>>>
>>>>> Why? When I type
>>>>>
>>>>> $ ns
>>>>>
>>>>> I get
>>>>>
>>>>> Usage:      host [-v] [-a] [-t querytype] [options]  name  [server]
>>>>> Listing:    host [-v] [-a] [-t querytype] [options]  -l zone  [server]
>>>>> Hostcount:  host [-v] [options] -H [-D] [-E] [-G] zone
>>>>> Check soa:  host [-v] [options] -C zone
>>>>> Addrcheck:  host [-v] [options] -A host
>>>>> Listing options: [-L level] [-S] [-A] [-p] [-P prefserver] [-N
>>>>> skipzone]
>>>>> Common options:  [-d] [-f|-F file] [-I chars] [-i|-n] [-q] [-Q] [-T]
>>>>> [-Z]
>>>>> Other options:   [-c class] [-e] [-m] [-o] [-r] [-R] [-s secs] [-u]
>>>>> [-w]
>>>>> Special options: [-O srcaddr] [-j minport] [-J maxport]
>>>>> Extended usage:  [-x [name ...]] [-X server [name ...]]
>>>>>
>>>>> What is the problem? Please help!
>>>>>
>>>>>
>>>>>
>>>>
>>>> It looks like you are not invoking "ns" the network simulator but
>>>> another
>>>> program named "ns" that is a name service.  If you type "which ns" you
>>>> will
>>>> see what program is being invoked when you simply type "ns".  To work
>>>> around
>>>> this, try typing the absolute path to the ns binary that you want to
>>>> invoke,
>>>> such as "/usr/local/bin/ns xxx.tcl".
>>>>
>>>>
>>>>
>>>
>>> Tom
>>>
>>> You are right, it is invoking ns in '/usr/bin/ns' every time I type
>>> ns. I tried the absolute path as you suggested and it works! Well not
>>> really.
>>>
>>> I get the following error now
>>>
>>> $ ns: finish: couldn't execute "nam": no such file or directory
>>>      while executing
>>> "exec nam ptrace.nam &"
>>>      (procedure "finish" line 6)
>>>      invoked from within
>>> "finish"
>>>
>>> What is happening here?
>>>
>>> So now I have two problems. First, how do I avoid typing the absolute
>>> path every time I want to run ns-2? Could I rename the name of the
>>> ns-2 executable file - would that simply do?
>>>
>>> And also, what is this second error?
>>>
>>> Thanks for your help - sorry for the delay in this reponse!
>>>
>>> Siraj
>>>
>>>
>>
>> Hello again
>>
>> Following up on my previous message, just want to confirm that I had
>> problems in the path so thats why ns-2 wasnt working. Now it works
>> fine, but I still dont know how to avoid typing the entire absolute
>> path every time.
>>
>> Please help!!
>>
>> Thanks
>>
>> Siraj
>>
>>
>
> Siraj,
> The system tries to find any executables (the commands we give on the
> prompt) in the PATH. You can know what is the current path by typing 'echo
> $PATH' . So, when we type 'ns' it tries to find that in that path. Now in
> your case, as you say you already have changed the PATH by adding <ns2> bin
> path as suggested during installation. Now, if there are two SAME NAMED
> executable in two different directories, (both of them are in the PATH) then
> the first found in the order of the PATH is executed. This is why when you
> type 'ns' it executes the /usr/bin/ns which is something else we dont
> want... One way to overcome this problem (to get rid of typing the FULL path
> to our ns) is to rename/remove the 'ns' in usr/bin/ folder to some other
> name, say 'ns_different'. Of course here I assume that you need not use that
> ns at least in near by future. (How will you use it if you don't know what
> it is???) In future, however, if you need it you must use it as
> 'ns_different' command.
> Now for the 'nam' related error, I suppose that nam should not have
> installed at all. You can check it by checking the presence of
>>
>> <ns-allinone-2.33>/nam-1.13/nam.
>
>> If 'nam' is not there than it is not installed at all. However if it is
>> there then again the problem is related to the path. You can confirm the
>> proper installation by executing (full pathed command)
>> '<pathtoallinone>/nam-1.13/nam <your nam file> '. You can correct this path
>> related problem as discussed above for the NS.
>
> bye
> Mayur
>
Mayur

Thanks for your helpful reply. Makes sense. The current setup on my
machine is dedicated to using ns-2. I would like to, however, use the
internet (browse) from time to time. I am just wondering whether
renaming the usual name service (ns) would have any impact on the
access to the internet or any other hidden/system services?

If not, then I wouldnt mind just commenting out the entry for the ns
program for now. If need be, I can simply reinstate it then later.

Any thoughts on this from anyone would be great.

Thanks

Siraj