CentOS 5 Server :: Pacemaker - Ping The Gateway To Avoid Split-brain?
May 26, 2010
I've set a two-node cluster using Pacemaker/OpenAIS. I have only one network and if I break this one, the communication between node is interrupted ... With a ClusterIP resource, when network is breaked, then each node start the ClusterIP => 2 same IP .. Is there a way to define the prefered location of a resource when connection between these nodes is broken ?
A <==> B
If one of the node lose the network, then follow a previously written rule : start resource on A (for example). B will know than it's not the prefered node and so, will stop to serve. Possible ? This is because if both node are connected, but a problem between these node occur and client can join both node ... then the split brain is problematic ... A better solution is to add a rule when the split-brain occurs : all node wich can't reach the gateway have to stop all resources ... And so, if it's A wich lose the network, service will start on B and only B without any problem ...
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),
So, I have an Virtual Machine running CentOS 5.4. It sits behind a hardware firewall which also does NAT'ing. I've set up plenty of these, so I know for sure the firewall and NAT rules are set up correctly. From the host, I can ping anything in my subnet and the gateway. But I can't ping anything else beyond the gateway. I can perform DNS queries and when I try to ping, it finds the appropriate IP address.But from the outside, I can ping the PUBLIC address (It's a 1 public to 1 private address NAT, not 1 public to multiple private). I've tried it with IPTABLES on and off, with no change.
I have configured bonding on 64 bit centos 5.4 I have to put the machine to a different VLAN for that i did the Ip change and restated the network. but i cant ping the gateway or any other server in that network. the cofig files are as follows
vi /etc/modprobe.conf alias eth0 bnx2 alias eth1 bnx2 alias scsi_hostadapter aacraid alias scsi_hostadapter1 ata_piix alias usb-controller ehci-hcd alias usb-controller1 uhci-hcd alias bond0 bonding options bonding mode=1 miimon=100 [Code].....
Back in April I set up a Ubuntu DHCP server and a multiple VLAN network [URL] to migrate our various servers, workstations, etc off the 192.168.1.1 /24 network that everything was on because we where running out of address space. I built out the new network and everything worked great except our AD server would never get an IP address from the DHCP server (static reservation) and even if I set the IP statically on the AD server it couldn't ping the gateway and noone could log in. After several attempts to resolve this, including bringing in outside help, we where never able to figure out what the problem was.
Now 6 months later I have time to revisit the issue without effecting the live network. I used Acronis and imaged the AD server last Friday, cloned it on to another box with the same hardware, and put it up on the new network that's been sitting unused for the last 6 months. Today when I statically set the IP on the AD server (which is what I want) it connects and I can ping it's gateway 192.168.1.1 and all the way across vlans to a test sales agent workstation at 192.168.8.xxx on vlan 800 but only if I statically assign the agents station an IP address. When I try to get an IP address via DHCP it fails as destination unreachable. Nothing has changed in the last 6 months on the DHCP server but now it for some reason can't ping its default gateway 192.168.1.1. All of the config files are the same as they where left from the post linked above aside from the vlan id's used where changed from 1's to 100's (i.e. vlan 3 is now vlan 300) /etc/network/interfaces
Code:
auto lo iface lo inet loopback auto vlan100 iface vlan100 inet static
[code]....
why it can't reach the gateway, when I do a tcpdump I can see the DHCP requests come in on eth0 but the server never responds and I'm pretty sure its because it isn't "seeing" them since it thinks there isn't a network connection but I don't know how to trouble shoot to find out where the problem lies.
Back in April I set up a Ubuntu DHCP server and a multiple VLAN network [URL] to migrate our various servers, workstations, etc off the 192.168.1.1 /24 network that everything was on because we where running out of address space. I built out the new network and everything worked great except our AD server would never get an IP address from the DHCP server (static reservation) and even if I set the IP statically on the AD server it couldn't ping the gateway and noone could log in. After several attempts to resolve this, including bringing in outside help, we where never able to figure out what the problem was.
Now 6 months later I have time to revisit the issue without effecting the live network. I used Acronis and imaged the AD server last Friday, cloned it on to another box with the same hardware, and put it up on the new network that's been sitting unused for the last 6 months. Today when I statically set the IP on the AD server (which is what I want) it connects and I can ping it's gateway 192.168.1.1 and all the way across vlans to a test sales agent workstation at 192.168.8.xxx on vlan 800 but only if I statically assign the agents station an IP address.
When I try to get an IP address via DHCP it fails as destination unreachable. Nothing has changed in the last 6 months on the DHCP server but now it for some reason can't ping its default gateway 192.168.1.1. All of the config files are the same as they where left from the post linked above aside from the vlan id's used where changed from 1's to 100's (i.e. vlan 3 is now vlan 300) /etc/network/interfaces
Code:
auto lo iface lo inet loopback auto vlan100
[code]....
why it can't reach the gateway, when I do a tcpdump I can see the DHCP requests come in on eth0 but the server never responds and I'm pretty sure its because it isn't "seeing" them since it thinks there isn't a network connection but I don't know how to trouble shoot to find out where the problem lies.
I am trying to get a Linux (Slackware 13.37) working in a Windows networking environment. The IT support for this organisation does not extend to Linux support, so I'm limited in what help I can get for this.
I'm trying to get to the point where I can get to the internet to download what I need on this Linux machine.
The situation is this (*fictitious addresses used) -My Linux machine uses a fixed IP address (10.100.150.21) My Windows machine uses a DHCP assigned IP address (10.100.150.213)Both Linux and Windows machine are configured to access the gateway server (10.100.150.1)So, I can ping the Linux machine from the Windows machine and vice-versa.I can ping the gateway machine from the Windows machine.I can browse Windows Shares on the network via SMB from the Linux machine.I CANNOT ping the gateway machine from the Linux machine with the Destination Host Unreachable message being the error message.
For actual internet access I need to access a proxy server but since the Linux machine can't even ping the gateway server, it fails to ping the proxy.Now, I have been told the gateway is a HW based router and for Windows machine they use some software for authentication to connect to the network. This software isn't available for Linux, so that's why I've been told to use a fixed IP address.My experience of networking is pretty basic and most of the Linux setup is done via running Slackware's setup program.
i just want to prevent from now on from all users maybe even root from adding other users to groups like wheel for example. I also want to know how can I prevent from all users to create new groups or add users to new one.real
I have been beating my head for the last few weeks on this problem, (although I have been taking the wrong approach, it seems).
I need a gateway to direct web traffic to three separate servers/domains. I have been trying to do this with both a dns server and , (seperatly), apache server to forward requests. The dns server was a no go, and <i can only get apache to redirect http and ftp.
After Googling this ALOT, I believe that what I need is a gateway server to redirect my traffic to the 3 different servers. I have been reading about using using nat and iptables for this and was wondering if anyone had any advice/suggestions on this. The other thought I had was to use something like pfSense to create the gateway, but I am still reading the documentation, and I am unsure if this approach will work.
I can ping my IP, and other PC in the same LAN, but I CANNOT ping the gateway on my 10.04LTS ubuntu. Other PC in the same LAN(Ubuntu 10.04LTS) could ping the gateway and my IP. I thought that (1)network cable is OK because I could ping the other PC in the same LAN.(2)Gateway is OK because other PC could ping it. (3)setting of operating system might be somehow wrong.
I have tried to restart the network several times and still not works. I followed the HOW-To debug tips and following is the results. Any suggestions?
My problem is simple, iam runing ubuntu 8.04 (ebox 1.4) , i have installed and configured PPTPD server, i can connect and ping users perfectly. BUT i dont getting any gateway address, in my case i have to get IP address 172.16.0.1 (PPTP server address).I tried to change localIP in pptpd.conf to 0.0.0.0 ,or my remote(ISP) address but nothing.Can someone explain to me how can i manually assign gateway IP address to PPTPD Server ???
I am accessing internet through Analog Proxy. ADSL modem has been connect to one of windows xp machine and by running Analog proxy, we uses internet by mentioning that machine's ip address. But how do i ping the default gateway in this case? Is it possible or not? If yes then please tell me how, because if i says # ping <anysite.com> it not pinging; its says host unreachable; means i will not be able to run wget too.
I am trying to ping from OEL 5.3. In one of google link; i read that :Does PING work through the Proxy Server? No, ping uses the ICMP protocol to communicate. Proxy only supports TCP and UDP packets. Ping will resolve the DNS name but go no further.
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.
When using gateway 196.214.15.X with ip 192.168.1.X all windows pc connect to internet and email but using the same range on rhel5 it cant even ping mailbox. Why is the ip masked, can u get software to trace the ip of the gateway from the windows pc, the 196 ip is I suppose a public ip as it is the ip of my lease line? How do I get the RHEL5 running internet using the same range as the windows boxes ??
Set up new server using RH 2.6.9-42.ELsmp on an old HP G4 server. But can't get network to work, can't ping any host, not even my gateway.
Verified cable by plugin a different pc on it, using same network ip address, etc, it worked fine, could ping gateway and other hosts on same segment. Are there any other files I could check to verify network card on server is good? it was working when it was configured as a windows server.
Presently this client access the net through following setup ADSL modem -> hub -> all computers
Now they want to do some kind of bandwidth control, content filtering. So I tried setting up squid with dansguardian. This is what I did ADSL -> linux server -> all computers.
The linux server has two NIC cards. One to the ADSL router and another to the local hub. This is how my squid.conf file looks like
Have set the gateway server as 121.x.x.1. Which is the gateway server of the ISP. Now I can ping the local network, but cant ping the gateway or any other website. Also I am unable to access the router administration page.
I have configured (bind) my server with multiple static IP. I can ping the main IP from outside but not the other IP . I can ping all the IP from localhost but not from the internet. I do not have any external firewall or blocking device. server is directly connected via modem. If anyone could advice me for why i cannot ping other Ip's
I have installed Centos 5 on a virtual machine (esx4i). I set it to obtain an IP address from the DHCP sever, which is a broadband router, it has been given an IP address of 10.10.11.159 the router is 10.10.11.1 but I can't ping the router and I can't get any access to the network! I have a SCO Openserver server on the same physical box and it works fine so I know the network card & cable is ok.
I have 4 centos5 apache webservers all on the same network, recently, 2 of the webservers have stopped being able to ping or browse one particular website where feeds are obtained from this site. I have checked and firewall and selinux settings are disabled. The two webservers are able to ping and browse other sites. Dns settings are the same for all 4 servers. traceroute for working and not working webservers are the same.
I have OpenVPN running successfully on a CentOS Linux server. All remote clients connect without a problem and can ping the server LAN (10.5.0.0/24) . The server address is 10.5.0.1. All network shares on the server are available to the remote clients via SAMBA shares and this works well.The problem is that I am unable to get the remote clients to access services on the LAN clients. For example, there is a webserver running on a Windows XP PC (on the server LAN @ 10.5.0.2) with no firewall enabled. The remote VPN clients can ping this webserver at 10.5.0.2, but cannot browse the webserver at [URL]. All clients on the server LAN can however browse the webserver. The remote clients are using Windows XP and VISTA with OpenVPN 2.1.1.
I am new to VPNs and networking, but from my research, it seems as if this may be a routing issue. I would appreciate any help you may give in getting the remote clients to access the services on the LAN clients (other than the server @ 10.5.0.1).
I am using CentOS 5.5, I installed squid3 in that machine. From my users machine i am not able to use our webmail address. Outlook shows pop3 error.cannot ping webmail address inside proxy.
Some time yesterday, I lost the ability to ssh my remote server, or even visit any webpages it hosts.
I've explored hosts.deny, /var/log/secure and even turned iptables off to see if it would fix anything. To no avail. Here's what my ssh login attempt looks like:
I am using an virtual machine. where I need to ping from one machine to another. earlier I was able to ping. But after going to google.com once, I cannot ping back to this machine.
But if I gave ping -I eth1 <IP> then I can ping.
I cannot install any package, so tell me solution which includes not installing any package.
I installed openSUSE on one of my work system. The network port wasn't working when I was installing, but works fine now (checked in Windows). But for some reason, I am not able to configure the network. I used both Dynamic and Static IPs (both work fine in Windows) but still no go. I am using Yast Control Center for this purpose. I can't even ping the default gateway when I am using custom settings. When I use dynamic settings, it says Unreachable Network.
I've found plenty of resources that state how to converge the installation cds into a dvd, but does anyone know of a way to take a dvd iso and split it into the multiple installation cds?
Also, I know it's possible to just download the cd isos, but that's not the goal of this exercise.
I have Linux server with VMware Server 1.0.8. When I creating a virtual machine, I can not "send" a PING to the virtual machine. In the virtual machine, I have installed CentOS 5.3 (32bit). In the virtual machine I have defined the addresses IP. So, whey I can't "sent" a ping to the virtual machie? I have to set something on the Linux server?
I have a file of +1 1GB in size. I want to split it in either 100MB rar files or 100MB zip files.
Anybody know what command I need for this?
Please keep it simple, I'm very new to linux. So I'm hoping somebody can give me a command in the lines of "blabla "put file name here" "put file size here" "put folder to rar/zip" here.
