Why linux traceroute uses UDP protocol, we have basic ICMP protocol which is used in MS-windows tracert.Any specific use of traceroute using with UDP,TCP than ICMP?Windows is displaying all HOPs address but linux printing *.*.*
View 8 RepliesCode: # traceroute -I 69.12.32.2 Note: the -i and -I options were exchangedfor compability with LBL traceroute Use -I for ICMP, and -i <ifname> to specify the interface name unable to create ICMP send socket: Permission denied Note that the command was done as root. This worked in 11.3.
And yes, it works without the "-I". But it should work with the "-I". One shouldn't have to boot into Windows, just to run "tracert" there.
I am setting up a virtual server. Ubuntu 11.04, "minimal provider image".UFW was disabled by default. I set it to default deny. Allowed HTTP, SSH and other standard stuff, and enabled it. All seems to be OK. Adding one rule to block some annoying security scanners causes ping not to work. I'm not an Iptables expert, but it looks OK to me. I got it from some website, rather than invented it myself, but modified to to fit the ufw config file syntax. What in that rule prevents pings?!? It seems completely unrelated.
View 1 Replies View RelatedIf I traceroute to google, it hits my router and stops there. Generically, my Setup is this. AT&T Uverse residential gateway ---> wired to 54g router running tomato ---> wireless ethernet bridge to 54gl router running tomato in another room ---> wired to ubuntu and win7 box.
The ATT RG hands its external IP over the the 54g running tomato. the 54gl running tomato is a wireless ethernet bride in the den running the same with 2 machines wired to. The two machines are static IP to the first router, which does all DCHP, stuff like that. The Windows box is fine. The subnets are the same. What should I be looking at to figure this out? This is the only "network" issue I have come across.
how to read a Traceroute readout.
View 14 Replies View RelatedI am trying to traceroute to google.com
When i do it looks like this
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It does this no matter what site I go to. also the 192.168.16.10 is the untangle server
The command does work for local Ips
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When I try traceroute it only gives me stars as output. For example:
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me@desk:/etc/udev/rules.d$ traceroute taobao.com
traceroute to taobao.com (121.14.24.241), 30 hops max, 60 byte packets[code]....
It gives me some output when tracerouting to other computers within my network:
As i've installed the new fedora update packets ,i've seemed to develope a strange networking problem .. Network description Fedora 15 with 3 LAN adaptors eth0 > LAN (IP address 192.168.0.254)eth1 > network connected to a pppoe conection eth2 > WAN to another provider. Ok so let's ignore eth2 because i've disable mangle(i was using trafic shifting on some ports). So now i'm using it as a simple NAT server .. so the problem is : >>my server is not responding to the traceroute command is it should .. the network works thou but this is what i get. C:UsersDUAL>tracert google.ro
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I've used linuxquestions.org from time to time, but never needed to register until now.An in-depth explanation of this issue is already described over here: [URL], so I will merely quote it again here - it seems nobody knows the solution over at Ubuntu's forums...:
Quote: I recently switched my home server from debian lenny to ubuntu maverick. I've managed to port all my configs and stuff and so far I'm very happy. There's one tiny thing that's griping me, that I never experienced before with debian's (older) packages/configuration... Here's the situation: My server dials up 2 pppoe (adsl) interfaces (different isp's) with split internet routes.
If I run a general traceroute to an internet IP, all the hops which are not routed via the same interface as the destination host/IP, will appear as "* * *" in the traceroute. This was never the case before and it would be preferred to see the IP's of all routers along the way regardless of whether they are routed... (I used to be able to see IP's like 10.0.0.x before through INTERNET traceroutes if they were hops along the way [IP's which would be unreachable if traced directly], and that's no longer the case) - isn't this kinda defeating the point of traceroute?
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how to identify the icmp packets & marking. this below icmp packets marking is not working.
iptables -t mangle -A PREROUTING -p icmp -j MARK --set-mark 0x5
iptables -t mangle -A PREROUTING -p icmp -j RETURN
with the help of port no or any other how can i identify the icmp packet ?... This below two is working fine
iptables -t mangle -A PREROUTING -p tcp -j MARK --set-mark 0x2
iptables -t mangle -A PREROUTING -p tcp -j RETURN
iptables -t mangle -A PREROUTING -p udp -j MARK --set-mark 0x3
iptables -t mangle -A PREROUTING -p udp -j RETURN
I run a linux box as a gateway behind a satellite modem. The internet link over the satellite modem is only 1mbit so the usage often reaches 100% when someone is downloading/uploading something. I am seeing my ping return time jump from 700ms to 6000ms if someone tries to upload a file (by sending a attachment in a email etc). The satellite operator is saying this is normal, but I have my doubts.
Has ICMP got a lower priority? Should I really be seeing this behaviour? I understand that if it was a TCP packet then it would just be queued until the previous acknowledgement has been received. And if it was a UDP packet then it would have been dropped, but how does ICMP deal with these situations during heavy traffic?
Is there a way to set the IP that's returned in an ICMP TTL exceeded packet? Reason I ask is I have an edge router with several upstreams, and several downstream routers, and when I traceroute to it I would like only one of it's IP's to show up in the trace (Instead of each . Much like some of the larger ISP's do to mask the IP and hostname of their internal routers.. Is this possible?
View 2 Replies View RelatedI have One Server which is having IP 10.176.0.155. I want that client 10.176.0.135 is not able to ping this server only & cane it is possible to block through hosts.
View 1 Replies View RelatedI have a C program which does.
1. Creates a UDP socket
2. Send the UDP Request packet to the TFTP server.
3. If the TFTP server is not listening in the 69 port, the remote machine send an ICMP ("Port Unreachable") message.
Is there a way to receive a notification from the Linux kernel on receipt of an ICMP packet to the created UDP socket.
icmp request from an ip that is in the same network as one of the local interfaces is not responded to, if the ping request is received via an interface in a different network. Is this some security feature?
Consider the below network
x.1|RTR1|-y.1---------y.2-|RTR2|-z.2------z.3-|LNX|-x.3
RTR - Router
x.1 -> 192.168.x.1
LNX - Linux machine
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So im trying to get an icmp tunnel setup using ptunnel. When I run it under the same network and use to connect to RDP, it works fine, however when go outside my network and connect in, it does not get anywhere. I can confirm that I have forwarded ICMP packets to the server (if I ping the external ip it will show the status of the server if I unplug it) and that the server is showing signs of registering it.
On the client it just tries to resend the packet "Resending packet with seq-no 0" Over and over Firewall is off for testing so thats not the issue.
From what I've read, when linux sends a ping it sends without the netmask, so windows server assumes it must be a broadcast? Why doesn't linux send a netmask with a ping?
View 6 Replies View RelatedI tried to ping some of the pcs on the local network but for those with icmp disabled it doesn't work. I've used
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nmap -sP 192.168.2.0/24
Installed Ubuntu Server 10.10, included Apache, PHP, and OpenSSH. Apache is up and serving pages, I can connect using PuTTY no problem. Server responds to a pingHowever, attempting to use ping or traceroute from the server results in a Destination Unreachable. Happens even for other 192.168.1.10x boxes on the local network
View 1 Replies View RelatedWhy firewalls does not allow ICMP echo request packets. Why are pings not allowed to certain systems?
View 1 Replies View RelatedCan any one tell me a network monitoring tool which can monitor remote connectivity and generate a comprehensive report about the link state like up/down, error timings, increase in latency and packet loss rate.
View 3 Replies View RelatedOn my system, I have built my own tunneling protocol, where I relay packets over a non-standardized but verified medium. What I do is capture the packets using iptables and NFQUEUE, relay them over my medium, and at the other end I reinject them using raw sockets. The packet going into the tunnel is exactly the same as the one coming out, verified. The problem is that this doesn't work for ICMP Ping (Echo Request) if the destination of the ping is the same as the tunnel endpoint. If the destination is not the same as the tunnel endpoint, the ping packet is rerouted and arrives as it should at the receiver, and the ping reply comes back to the sender. Does anyone know whats going on? Isn't it possible to send raw icmp to yourself? If not, anyone have an idea what I should do instead?
View 1 Replies View RelatedI set up a static IPv6 address and a gateway in /etc/network/interfaces. However, a bad router in my network environment alway send wrong ICMP router discovery messages to me. So I have got extra (wrong) IPv6 address and gateway, and the routing is confused. On Windows Servers, I can use "netsh interface ipv6 set interface "Local Area Connection" routerdiscovery=disable" to disable ICMP router discovery. But I don't know how to disable it on Ubuntu 9.10. How could I disable ICMP router discovery for IPv6?
View 4 Replies View RelatedWhen I ping our Microsoft Windows terminal server "cluster" farm, I get ICMP warnings that there are duplicate packets. I am able to rdesktop to the cluster with no problems. We are trying to setup nagios to run on this Ubuntu configuration and nagios is reporting the following error:
"PING WARNING - DUPLICATES! Packet Loss=0%, RTA=.98ms.
FPing reports duplicates as well. Is there a setting in the Arp table that needs to be set differently because the "Cluster" MAC address isn't an actual hardware MAC but a virtual MAC address?
Struggling to get my Linux server accept ICMP redirects not originating from default gateway. No problem to get it working if the redirects is originating from def gw.I know it's not a good solution security wise, but my network is so cluttered I'm forced to do so.
View 1 Replies View RelatedI have a dedicated host on my lan to monitor other hosts/services using Nagios. I'm in the process of migrating to Zabbix on that host to perform the same purpose. Both Nagios and Zabbix monitor icmp ping latency (Nagios uses ping, Zabbix uses fping) and over time the latency to other hosts grows until threshold alarms are triggered. In one week, the average latency grows from sub-millisecond to over 100 milliseconds, and continues to grow until the Nagios host is rebooted. I have verified the latency numbers using ping/fping from the command line on the Nagios host.
The problem is that pings from the monitored hosts to the Nagios host show normal latency at the time the Nagios host is showing high latency from itself to the monitored hosts. The Nagios host and monitored hosts are all connected to the same Dell 24 port gigabit switch. I already posted this question on the Zabbix forums with a graph of the latency but there were no answers. [URL] why the icmp ping latency is growing over time and how I can fix it short of rebooting the host on a schedule.
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I am unable to ssh a Linux box from other Linux boxes; also tried to window putty.Although I am getting the password prompt instantaneously.So far, by comparing logs of other server, I am just able figure out that "debug2: callback start" is not coming in ssh -vvv logs.
View 2 Replies View RelatedI want to configure linux CentOS 5 as a router using iptable, .Im new in linux so I need the steps to do that
View 5 Replies View Relatedhow I run a traceroute on 11.04?
View 7 Replies View Relatednaman@naman-laptop:~$ traceroute google.co.in
google.co.in: Name or service not known
Cannot handle "host" cmdline arg `google.co.in' on position 1 (argc 1)
Then I tracked the IP address of google.com on [URL] and tried
naman@naman-laptop:~$ traceroute 74.125.77.99
traceroute to 74.125.77.99 (74.125.77.99), 30 hops max, 40 byte packets
connect: Network is unreachable
I have to use my college proxy server to connect to the Internet. When I traceroute to a host within the LAN there is no problem. What should I do to be able to traceroute to a host outside my local network?