linux ppp routing problems - can't ping anything!

I've been trying to get ppp setup on my linux box. Everything seems
to connect fine. I have an ip for the ppp0 interface as indicated
below


ppp0 Link encap:Point-to-Point Protocol
inet addr: 142.150.134.82 P-t-P:142.150.128.47
Mask:255.255.255.255
...

and my routing table has the following entries:

Destination Gateway Genmask Flags Metric Ref
Use Iface
142.150.128.47 0.0.0.0 255.255.255.255 UH 0 0
0 ppp0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0
0 lo
0.0.0.0 142.150.128.47 0.0.0.0 UG 0 0
0 ppp0


When I ping, virtually nothing responds! I tried pinging
142.150.128.47 (the address of the server that gave me the ip) but I
get no response. However the name resolver seems to be working
because when I ping for example www.yahoo.com I get:
PING www.yahoo.com (216.109.117.204) from ...
but no response after that!

The only successful pings I can make are to 142.150.134.82 and
127.0.0.1.

Is my routing table setup properly? Do I have to setup a route from
my local address to the server's address (ie 142.150.134.82 to
142.150.128.47)

Thanks in advance

> When I ping, virtually nothing responds! I tried pinging
> 142.150.128.47 (the address of the server that gave me the ip) but I
> get no response. However the name resolver seems to be working
> because when I ping for example www.yahoo.com I get:
> PING www.yahoo.com (216.109.117.204) from ...
> but no response after that!

are you sure your peer isnt dropping icmp packets?
try doing a traceroute - this will use udp packets.

(E-Mail Removed) (Kaman) writes:
> The only successful pings I can make are to 142.150.134.82 and
> 127.0.0.1.

It sounds like the link itself isn't working.

> Is my routing table setup properly? Do I have to setup a route from
> my local address to the server's address (ie 142.150.134.82 to
> 142.150.128.47)

No, that doesn't sound like it's related to the problem. It sounds
like there's some sort of communications failure in the link.

There are many things that could cause such a thing to happen. Please
post more details -- debug logs, configuration files, and information
about the equipment you're using.

(If, by chance, you're using a "winmodem," then stop. Get a real
modem first.)

--
James Carlson, IP Systems Group <(E-Mail Removed)>
Sun Microsystems / 1 Network Drive 71.234W Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757 42.497N Fax +1 781 442 1677

"Tim Warnock" <(E-Mail Removed)> writes:
> > When I ping, virtually nothing responds! I tried pinging
> > 142.150.128.47 (the address of the server that gave me the ip) but I
> > get no response. However the name resolver seems to be working
> > because when I ping for example www.yahoo.com I get:
> > PING www.yahoo.com (216.109.117.204) from ...
> > but no response after that!
>
> are you sure your peer isnt dropping icmp packets?
> try doing a traceroute - this will use udp packets.

Good point, though traceroute isn't exclusively UDP -- the messages in
return are ICMP Time Exceeded messages, and if there are draconian
filters in place, you'll still not get replies.

Try "telnet www.yahoo.com 80" and see if that works.

--
James Carlson, IP Systems Group <(E-Mail Removed)>
Sun Microsystems / 1 Network Drive 71.234W Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757 42.497N Fax +1 781 442 1677

Kaman wrote on 20.07.2004 16:17:

> I've been trying to get ppp setup on my linux box. Everything seems
> to connect fine. I have an ip for the ppp0 interface as indicated
> below
>
>
[Routing table]
>
> When I ping, virtually nothing responds! I tried pinging
> 142.150.128.47 (the address of the server that gave me the ip) but I
> get no response. However the name resolver seems to be working

This indicate that your connection is working, at least to your nameserver.

> because when I ping for example www.yahoo.com I get:
> PING www.yahoo.com (216.109.117.204) from ...
> but no response after that!

You actually _can't_ ping yahoo. This is to prevent PoD attacks.
Try a pingable address like www.nasa.gov.

> The only successful pings I can make are to 142.150.134.82 and
> 127.0.0.1.

So your loopback is working

> Is my routing table setup properly? Do I have to setup a route from
> my local address to the server's address (ie 142.150.134.82 to
> 142.150.128.47)

Your routing looks quite normal.
Somehow I miss your internal IP.
What about tracerouting?
What happens if you do "nmap -vsP 142.150.128.0/24"? This will ping all
machines in your segment.


--
HTH

Walter

In comp.protocols.ppp Kaman <(E-Mail Removed)> wrote:
> I've been trying to get ppp setup on my linux box. Everything seems
> to connect fine. I have an ip for the ppp0 interface as indicated
> below

> ppp0 Link encap:Point-to-Point Protocol
> inet addr: 142.150.134.82 P-t-P:142.150.128.47
> Mask:255.255.255.255
> ...

> and my routing table has the following entries:

> Destination Gateway Genmask Flags Metric Ref
> Use Iface
> 142.150.128.47 0.0.0.0 255.255.255.255 UH 0 0
> 0 ppp0
> 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0
> 0 lo
> 0.0.0.0 142.150.128.47 0.0.0.0 UG 0 0
> 0 ppp0

The routing is correct.

> When I ping, virtually nothing responds! I tried pinging
> 142.150.128.47 (the address of the server that gave me the ip) but I
> get no response. However the name resolver seems to be working
> because when I ping for example www.yahoo.com I get:
> PING www.yahoo.com (216.109.117.204) from ...
> but no response after that!

Then DNS lookup succeeds.

> The only successful pings I can make are to 142.150.134.82 and
> 127.0.0.1.

I'd suspect the peer (ISP connection host) is dropping ping echo-requests
to avoid DoS attacks. If everything works except for pinging then that
is almost certainly what's happening.

> Is my routing table setup properly? Do I have to setup a route from
> my local address to the server's address (ie 142.150.134.82 to
> 142.150.128.47)

Yes, no.

--
Clifford Kite Email: "echo xvgr_yvahk-(E-Mail Removed)|rot13"
PPP-Q&A links, downloads: http://ckite.no-ip.net/
/* "PPPoE has many advantages for DSL service providers, and
practically none for DSL consumers."
- David F. Skoll */

In comp.protocols.ppp Walter Schiessberg <(E-Mail Removed)> wrote:
> Kaman wrote on 20.07.2004 16:17:

>> because when I ping for example www.yahoo.com I get:
>> PING www.yahoo.com (216.109.117.204) from ...
>> but no response after that!

> You actually _can't_ ping yahoo. This is to prevent PoD attacks.

Nonsense.

~# ping 216.109.117.204
PING 216.109.117.204 (216.109.117.204) 56(84) bytes of data.
64 bytes from 216.109.117.204: icmp_seq=1 ttl=51 time=203 ms
64 bytes from 216.109.117.204: icmp_seq=2 ttl=51 time=181 ms

--- 216.109.117.204 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1000ms
rtt min/avg/max/mdev = 181.970/192.522/203.074/10.552 ms

--
Clifford Kite Email: "echo xvgr_yvahk-(E-Mail Removed)|rot13"
PPP-Q&A links, downloads: http://ckite.no-ip.net/
/* "Be liberal in what you accept, and conservative in what you send"
RFC 1122 */

Clifford Kite wrote on 20.07.2004 18:13:

> In comp.protocols.ppp Walter Schiessberg <(E-Mail Removed)> wrote:
>
>>Kaman wrote on 20.07.2004 16:17:
>
>
>>>because when I ping for example www.yahoo.com I get:
>>>PING www.yahoo.com (216.109.117.204) from ...
>>>but no response after that!
>
>
>>You actually _can't_ ping yahoo. This is to prevent PoD attacks.
>
>
> Nonsense.
>
I actually tested it...

Walter

Walter Schiessberg <(E-Mail Removed)> writes:
> I actually tested it...

I think it's likely that _your_ ISP is doing the filtering. It works
fine for many of the rest of us. ("www.yahoo.com" is a CNAME
resolving to www.yahoo.akadns.net, which then resolves to an array of
p<xxx>.www.dcn.yahoo.com servers, at least when I look at it.)

% ping www.yahoo.com
PING www.yahoo.akadns.net (216.109.118.69) 56(84) bytes of data.
64 bytes from p6.www.dcn.yahoo.com (216.109.118.69): icmp_seq=1 ttl=50 time=26.6 ms
64 bytes from p6.www.dcn.yahoo.com (216.109.118.69): icmp_seq=2 ttl=50 time=26.0 ms
64 bytes from p6.www.dcn.yahoo.com (216.109.118.69): icmp_seq=3 ttl=50 time=23.2 ms

--- www.yahoo.akadns.net ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2021ms
rtt min/avg/max/mdev = 23.291/25.317/26.629/1.465 ms

--
James Carlson, IP Systems Group <(E-Mail Removed)>
Sun Microsystems / 1 Network Drive 71.234W Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757 42.497N Fax +1 781 442 1677

Here's a list of the relevant information to do with the ppp
connection. As for the type of modem I'm using, it's the USR
Sportster model 325686-03. Let me know if you see something wrong
with my scripts. (Just to let you know I've put *'s in place of my
username and password. ) If there is other information that may be
helpful in debugging this problem please let me know.



Thanks for all your help.

ifconfig output:
----------------

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

ppp0 Link encap:Point-to-Point Protocol
inet addr:142.150.128.245 P-t-P:142.150.128.13
Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:552 Metric:1
RX packets:3 errors:1 dropped:0 overruns:0 frame:0
TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:42 (42.0 b) TX bytes:63 (63.0 b)


route -n output
----------------

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref
Use Iface
142.150.128.13 0.0.0.0 255.255.255.255 UH 0 0
0 ppp0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0
0 lo
0.0.0.0 142.150.128.13 0.0.0.0 UG 0 0
0 ppp0


/etc/ppp/options
-----------------

# Uncomment the line below for more verbose error reporting:
lock
-detach
debug
noipdefault
modem
38400
crtscts
defaultroute
asyncmap 0
mtu 552
mru 552
0.0.0.0:0.0.0.0
/dev/modem
connect "/usr/sbin/chat -v -f /etc/ppp/pppscript"


/etc/ppp/pppscript
-----------------
TIMEOUT 60
ABORT ERROR
ABORT BUSY
ABORT "NO CARRIER"
ABORT "NO DIALTONE"
"" "AT&FH0"
OK "atdt4169780449"
TIMEOUT 75
CONNECT ""
name: \d********
word: \q********
in> "ppp default"


/var/log/messages
-----------------

Jul 20 18:03:11 amdlinux pppd[324]: pppd 2.4.1 started by root, uid 0
Jul 20 18:03:12 amdlinux chat[326]: timeout set to 60 seconds
Jul 20 18:03:12 amdlinux chat[326]: abort on (ERROR)
Jul 20 18:03:12 amdlinux chat[326]: abort on (BUSY)
Jul 20 18:03:12 amdlinux chat[326]: abort on (NO CARRIER)
Jul 20 18:03:12 amdlinux chat[326]: abort on (NO DIALTONE)
Jul 20 18:03:12 amdlinux chat[326]: send (AT&FH0^M)
Jul 20 18:03:12 amdlinux chat[326]: expect (OK)
Jul 20 18:03:12 amdlinux chat[326]: AT&FH0^M^M
Jul 20 18:03:12 amdlinux chat[326]: OK
Jul 20 18:03:12 amdlinux chat[326]: -- got it
Jul 20 18:03:12 amdlinux chat[326]: send (atdt4169780449^M)
Jul 20 18:03:12 amdlinux chat[326]: timeout set to 75 seconds
Jul 20 18:03:12 amdlinux chat[326]: expect (CONNECT)
Jul 20 18:03:12 amdlinux chat[326]: ^M
Jul 20 18:03:35 amdlinux chat[326]: atdt4169780449^M^M
Jul 20 18:03:35 amdlinux chat[326]: CONNECT
Jul 20 18:03:35 amdlinux chat[326]: -- got it
Jul 20 18:03:35 amdlinux chat[326]: send (^M)
Jul 20 18:03:35 amdlinux chat[326]: expect (name
Jul 20 18:03:35 amdlinux chat[326]: 28800/ARQ^M
Jul 20 18:03:36 amdlinux chat[326]: ^M
Jul 20 18:03:36 amdlinux chat[326]: Welcome to the
UTORDial high speed Dialin Facility^M
Jul 20 18:03:36 amdlinux chat[326]: ^M
Jul 20 18:03:36 amdlinux chat[326]:
14.4Kbps 416-978-1550^M
Jul 20 18:03:36 amdlinux chat[326]:
28.8Kbps 416-978-0449^M
Jul 20 18:03:36 amdlinux chat[326]: ^M
Jul 20 18:03:36 amdlinux chat[326]: Access through this service
requires the use of a personal UTORDial account. ^M
Jul 20 18:03:36 amdlinux chat[326]: All Staff, Faculty, and Students
of the University of Toronto are eligible^M
Jul 20 18:03:36 amdlinux chat[326]: for a UTORDial account. Please
consult URL=http://www.dialin.utoronto.ca/^M
Jul 20 18:03:36 amdlinux chat[326]: for additional information,
account setup and/or account management.^M
Jul 20 18:03:36 amdlinux chat[326]: ^M
Jul 20 18:03:36 amdlinux last message repeated 2 times
Jul 20 18:03:36 amdlinux chat[326]: User Access Verification^M
Jul 20 18:03:36 amdlinux chat[326]: ^M
Jul 20 18:03:36 amdlinux chat[326]: Bar Code/Username:
Jul 20 18:03:36 amdlinux chat[326]: -- got it
Jul 20 18:03:36 amdlinux chat[326]: send (\d********^M)
Jul 20 18:03:37 amdlinux chat[326]: expect (word
Jul 20 18:03:37 amdlinux chat[326]: *********^M
Jul 20 18:03:37 amdlinux chat[326]: Password:
Jul 20 18:03:37 amdlinux chat[326]: -- got it
Jul 20 18:03:37 amdlinux chat[326]: send (??????)
Jul 20 18:03:37 amdlinux chat[326]: expect (in>)
Jul 20 18:03:38 amdlinux chat[326]: ^M
Jul 20 18:03:38 amdlinux chat[326]: ^M
Jul 20 18:03:38 amdlinux chat[326]: cs4.dialin>
Jul 20 18:03:38 amdlinux chat[326]: -- got it
Jul 20 18:03:38 amdlinux chat[326]: send (ppp default^M)
Jul 20 18:03:38 amdlinux pppd[324]: Serial connection established.
Jul 20 18:03:38 amdlinux pppd[324]: Using interface ppp0
Jul 20 18:03:38 amdlinux pppd[324]: Connect: ppp0 <--> /dev/modem
Jul 20 18:03:42 amdlinux pppd[324]: local IP address 142.150.128.245
Jul 20 18:03:42 amdlinux pppd[324]: remote IP address 142.150.128.13


/var/log/debug
--------------

Jul 20 18:03:38 amdlinux pppd[324]: using channel 4
Jul 20 18:03:39 amdlinux pppd[324]: sent [LCP ConfReq id=0x1 <mru 552>
<asyncmap 0x0> <magic 0x7164c388> <pcomp> <accomp>]
Jul 20 18:03:41 amdlinux pppd[324]: rcvd [LCP ConfReq id=0x1 <asyncmap
0xa0000> <magic 0x3adf6ee> <pcomp> <accomp>]
Jul 20 18:03:41 amdlinux pppd[324]: sent [LCP ConfAck id=0x1 <asyncmap
0xa0000> <magic 0x3adf6ee> <pcomp> <accomp>]
Jul 20 18:03:42 amdlinux pppd[324]: sent [LCP ConfReq id=0x1 <mru 552>
<asyncmap 0x0> <magic 0x7164c388> <pcomp> <accomp>]
Jul 20 18:03:42 amdlinux pppd[324]: rcvd [LCP ConfRej id=0x1 <mru
552>]
Jul 20 18:03:42 amdlinux pppd[324]: sent [LCP ConfReq id=0x2 <asyncmap
0x0> <magic 0x7164c388> <pcomp> <accomp>]
Jul 20 18:03:42 amdlinux pppd[324]: rcvd [LCP ConfAck id=0x2 <asyncmap
0x0> <magic 0x7164c388> <pcomp> <accomp>]
Jul 20 18:03:42 amdlinux pppd[324]: sent [IPCP ConfReq id=0x1 <addr
0.0.0.0> <compress VJ 0f 01>]
Jul 20 18:03:42 amdlinux pppd[324]: sent [CCP ConfReq id=0x1 <deflate
15> <deflate(old#) 15> <bsd v1 15>]
Jul 20 18:03:42 amdlinux pppd[324]: rcvd [IPCP ConfReq id=0x1
<compress VJ 0f 00> <addr 142.150.128.13>]
Jul 20 18:03:42 amdlinux pppd[324]: sent [IPCP ConfAck id=0x1
<compress VJ 0f 00> <addr 142.150.128.13>]
Jul 20 18:03:42 amdlinux pppd[324]: rcvd [IPCP ConfNak id=0x1 <addr
142.150.128.245>]
Jul 20 18:03:42 amdlinux pppd[324]: sent [IPCP ConfReq id=0x2 <addr
142.150.128.245> <compress VJ 0f 01>]
Jul 20 18:03:42 amdlinux pppd[324]: rcvd [LCP ProtRej id=0x2 80 fd 01
01 00 0f 1a 04 78 00 18 04 78 00 15 03 2f]
Jul 20 18:03:42 amdlinux pppd[324]: rcvd [IPCP ConfAck id=0x2 <addr
142.150.128.245> <compress VJ 0f 01>]
Jul 20 18:03:42 amdlinux pppd[324]: Script /etc/ppp/ip-up started (pid
328)
Jul 20 18:03:42 amdlinux pppd[324]: Script /etc/ppp/ip-up finished
(pid 328), status = 0x0