Ubuntu Networking :: DUP When Pinging Default Gateway. No Internets?
Jan 30, 2011
I had a router crap out yesterday. I'd been testing out a new one for the last few days and just reconfigured it to be the main. Took the old one down and everything in my house (Windows 7 PC, XP Files server, Ubuntu PC , windows 7 laptop, android tablet, ps3, etc) seems to be working fine whether it be hard wired or wifi. All except my ubuntu 10.04 laptop. It worked fine before the swap so I can't figure out what's going on.
I'm able to connect to the new SSID without issue but I can't resolve any external names and when I try to ping the default gate way every other packet has (DUP!) behind it. If I'm hardwired I don't get the dup! when pinging the default gateway but I still can't resolve any external names. I have provided the results of an ifconfig and the results of a ping to the default gateway below.
cooley@Quigon:~$ ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=2.98 ms
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=3.04 ms (DUP!)
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=3.50 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=5.72 ms (DUP!)
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=8.09 ms
I have installed ubuntu 9.04 Jaunty server from disk. I am connect to my corporate internet. I have put in my http_proxy everywhere I can find to put it. I am getting an ipaddress, gateway, broadcast,etc. My wired is connected. When I try to ping my default gateway it times out. %100 packet loss. I get the ipaddress of the gateway from the (route command).
My configurations on /etc/network/interfaces is correct(I am on another computer so I can't copy and paste) and I even tried updating the drivers for NIC card. I am using a Intel 82567LM-3. I have been working on this longer than I care to admit.
Im trying to achieve the multiple uplinks/provider found on LARTC.org. I have to get the IP addresses from my interfaces (EF1 and EF2) by using a script, but i dont know where to look at for the default gateway from each interface which got their ip address from my ISP.
I have a computer with two interfaces: a fixed connection (eth1) and a modem (ppp0). My goal is to receive UDP packets from both connections concurrently (using the recv() function). The problem is, that the received packets reach the application only when the default gateway is set to that interface's address. For example, if I set the default gw to be in the eth1 subnet, only packets from eth1 reach the application. Other packets are received in the interface (checked using tcpdump), but they seem to be blocked somewhere. The policy defined in iptables is "ACCEPT" for all incoming packets, with no rules at all. I would like to know how to overcome this problem, and anyway how is the default gateway related to incoming UDP?
I have a dual-homed Debian server running squid, but not acting as a router. Simplied network diagram is below - there are other local hops between the gateways and the Internet.
Code: (eth0 @ 192.168.44.2) <--> (Gateway1 @ 192.168.44.1) <--> Internet (eth1 @ 192.168.55.2) <--> (Gateway2 @ 192.168.55.1) <--> Internet
Using Gateway1 gives a very fast, but not always reliable route to the Internet. Using Gateway2 gives a slower, but more reliable route to the Internet. The server uses Gateway1 as the default gateway.
I have written a script that pings three hosts on the Internet, and if all three are down, switches the default gateway to Gateway2. This part seems to be easy, but I'd like know if there is a way of routing a ICMP/ping out eth0 to a host, with all other traffic to the host going out eth1, so I can determine if the Internet is reachable via Gateway1 again.
I am realtively new to BGP. I use BGP in my network to advertise my /20 subnet. What i would like to know is what is the point of accepting routes from your neighbouring AS(ISP)?My ISP has given me a default gateway, and no matter what I want to reach on the internet I have to go through that default gateway, so why populate the routing table with soo many routes?also, as i understand it, there are 3 kinds of routes that you can accept, those are full routes, directly connected routes and default routes. What is the diffrence between them and again how do they affect routing since my network only has the one default gateway?
I posted it on another forum, but could not get response,So I have this cenOS, Ubuntu and windows operating system running on virtual machines.Now I gave them manual ip address, both ubuntu and windows machines can ping the default gateway, but not the CentOS.It should forward 0.0.0.0. to my cisco router address(192.168.5.254),
I'm looking for a method to assign a default gateway via dhcp randomly depending on ether the last char of the mac being odd or even, or the time the user connects. Is there a good reliable way to achieve this?
I have installed dhcp-server on ubuntu. And server is providing ip address to clients (Window machines) but not default-gateway but I have another network in my network and same configuration and same dhcp-server provides every information.
I've been struggeling with this for a few hours now, googleing and so on trying to find an easy way to just switch which device I want as primary for internet connections. After long battles I'm at a loss, this is the current automatic routing
Code: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 85.225.76.0 0.0.0.0 255.255.252.0 U 1 0 0 eth0 85.225.76.0 0.0.0.0 255.255.252.0 U 2 0 0 wlan0
I need to place an Ubuntu machine on a network where I have a DHCP server which does not configure the Degault Gateway parameter (we don't want ordinary users to browse the internet). Is it possible to leave the machine using DHCP and define the Default Gateway manually (as in Windows XP i.e.)? How?
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.
Client which uses an ISP with a Linux machine (Server 1) with two network cards. Eth0 with ip 1.1.1.2 and gateway 1.1.1.1 these ip's is not public ip's and falls unders the isp's internal range, eth1 with the internal ip range. OpenVPN listen on eth0 for incoming connections. We want to connect to Server1 from external networks. Due to different reasons the isp could not get the routing sorted and give us an public ip on his network. We had to setup another bos (Server2) with eth0 2.2.2.5 and gateway 2.2.2.1 which is public ip's and eth1 with ip 3.3.3.5. Server 2 can communicate via the ISP internal network with server 1. I use DNAT to forward all incoming connections on server 2 to server 1 but the problem I have is that server uses its default gateway for the return packages and does not sent the reply back to server 2. My iptables rules looks as follows on server 2.
I'm using OpenWRT on a WRT54GS. I'm using wifidog in combination with openvpn. For those of you familiar with wifidog, my auth server is located at the other end of an openvpn tunnel and the "wifi dog gateway" is running on the WRT itself. I'm don't really think that wifi dog is the issue. Basically, I'm using openvpn with the "redirect-gateway" option which works well. In this mode, openvpn removes my current default gateway setting and adds the remote openvpn server as the default gateway (as it should). However, overnight, my default gateway on the local network keeps reapperaing (along with the openvpn one as well).
This causes confusion and I don't want any packets (But ovbiously the connection to the actual openvpn server) to go down this local gateway. Why do you think it reappears? Do you reckon openvpn is dropping connection and somehow the normal gateway is being added back? I *could* run a cron script which runs every minute or so with something like "route del default gw xx.xx.xx.xx" (where xx.xx.xx.xx is the default gateway which I don't want to be there) but that is quite messy and means that if I were to ever move the router I would need to reconfigure this and considering that I would like in the future to have many of these wifi dog gateways, this really isn't an ideal option (as every network will have a different default gateway).
I could not able to configure the default gateway ip address onto the system. i use the route command (" route add default gw 192.xxx.xxx.xxx eth0 ") to add a default gateway onto the routing table but it is "disappear" in the routing table when i had restart the service network.
Ive recently installed lubuntu 10.04 on an old sony vaio. ive been able to connect to the internet (satellite broadband) for a few months then no connection. the connection is fine so its definatly the network on the vaio. ive tried pinging to no avail.
I was doing some one-handed-one-fingered typing while talking on the phone. Due to lack of paying attention, I executed the following command: ifconfig eth0 1300 (was meant to be ifconfig eth0 mtu 1300) this of course killed the connection, so I got the box rebooted. This box functions as an openswan/firewall server. everything came up okay, end users are reporting no problems with the vpn or the firewall function. However, one service is failing because the route to localhost seems to be originating from eth0. when I `ping localhost`, the traffic dump shows the ping packet originating from the external address. On all my other boxes, when I ping localhost, the traffic originates from localhost. The reply to my ping behaves normally.
here is a dump of my pinging localhost: fw-ps:~/scripts# tcpdump -n -i lo listening on lo, link-type EN10MB (Ethernet), capture size 65535 bytes 10:00:01.885033 IP 194.246.23.22 > 127.0.0.1: ICMP echo request, id 6893, seq 12, length 64 10:00:01.885068 IP 127.0.0.1 > 127.0.0.1: ICMP echo reply, id 6893, seq 12, length 64
I considered trying to manually add some routes, but since the reply is working, I am not sure that is the problem. I also considered trying to change the default interface, but I don't want external traffic originating from the loopback.
I'm using kubuntu 9.10 desktop edition as a server and I set the IP statically, what happens is that when I ping it from another machine on the same network, I get intermittent packet loss (up to 80% and sometimes even higher). When I ping any other machine on the local network everything's fine with 0% packet loss. Packets go directly through switch, no router or anything in between.
I suspected wiring issues, but that doesn't seem to be the problem after I changed the wiring. I was connected to wireless and suspected that but no go either. Same thing when I turn wired. I just changed the ethernet card suspecting drivers but that's no good either. Iptables is a cleanslate installation, it's totally empty.
So I've been reading around a bit, and have found a few fixes for this Resolving Hosts problem, but none of them have fixed mine yet. Basically what happens is all browsers fail to load pages, pinging local network works, but pinging default gateway doesn't. Cannot ping external websites and cannot reach update or upgrade servers for ubuntu. All networking works as normal on all other PCs in house, as well as the windows 7 boot I have on my ubuntu PC.
What I've tried:Disabled IPv6 completely by preventing the module from booting up Manually setting network settings instead of using the router's DHCP server Changing DNS servers from ISP to Google public DNS to OpenDNS Buying a new ethernet card And a few other things I can't remember off the top of my head, none of which worked. From memory, all this just started happening out of the blue. I recently changed from Windows to Ubuntu, and was enjoying the switch but all of a sudden I couldn't get on the internet on Ubuntu.
Now, I'm not sure why, but I decided to ping myself. Not my LAN ip, but our router's WAN ip. It worked, albeit took a little while to return a response the first packet, but each subsequent packet after that was a normal speed (~0.5ms). The strange thing about this was that I found that for a few seconds after pinging myself, I could access the internet. After a few seconds though, it returns to it's resolving hosts self again, which another self-ping would fix.
Consequently, in order to browse, I have an open terminal constantly pinging myself which appears to be working. Not ideal, and certainly not something I would like to keep doing for long, but it works for now. I really like Ubuntu, but if I can't get this net thing fixed, I can't finish moving over from Windows!
Installed Fedora 10 with Mozilla-Firefox, I can get out on the internet by pinging outside IP's but Firefox browser returns cannot locate www. does anyone know what package I need so browser connects.
I'm having some difficulty with a internet/vpn setup. I have 3 network adapters on the server. 1x is used to connect it to the rest of the network 1x is used to provide internet (squid,dansguardian) 1x is used to connect to the vpn router
My interfaces file looks like this:
Code: # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). # The loopback network interface auto lo iface lo inet loopback
[Code]...
The problem that I have is this: When the gateway on eth2 is set to 10.0.2.2 the VPN works 100% but there is no internet. When the gateway on eth2 is set to 192.168.0.6 there is internet but no VPN.
So what I want to do is, route all traffic that is supposed to go to 10.0.2.0/24 and 10.0.3.0/24 to eth2 and all internet traffic to eth0.
I have installed eeebuntu NBR on my laptop and it looks great on a 17 inch widescreen. It looks so different from the usual interface that I get people ask about it and I can evangalise without being considered a boring weirdo! Anyway, I have one problem. Every time I boot I have to run the following command. Code: sudo /sbin/route add default gateway 192.168.0.1 How do I get this to happen automatically (as it normally does)?
I'm running wicd 1.7.0 on Kubuntu 10.04, with an Actiontec DSL wireless router (with an internal dd-wrt "bridged" router as well;Any idea what "magic" those lines are performing and if it's possible to make wicd do it all the time (instead of just the third time)?Very happy to pursue any debugging if anyone has any ideas, as it's pretty annoying to have to wait an extra couple minutes on every boot until connecting.
