Re: Cheap Gigabit switch will allow DHCP thru it?
Jeff Macdonald wrote: On Dec 29, 2007 12:31 PM, Bruce Labitt [EMAIL PROTECTED] wrote: I'm looking to add another hdhomerun tunerbox to my myth setup. I have a DHCP server running to give the existing tuner its IP address. Can I add a cheap gigabit switch to add the other tuner? Will the requests for IP address be routed to the server properly? I have a cheap netgear gigabit switch and all the devices do dhcp that are connected on it. I have found to my dismay, that I have my on board ethernet port (gigabit) connected to to my router (only 100Mbit). It is a dhcp client. My add on cheap ethernet card (100Mbit) is connected to the hdhomerun. It has the dhcp server for the hdhomerun(s). Is there a simple way to swap eth0 and eth1? I *think* this would work... I would want the 1Gbit interface to go the the switch and the hdhomeruns. It would have dhcp server. The 100Mbit interface would go to my router for the external interface. It would be a dhcp client, getting its IP from the router. I could just put in a gigabit ethernet card, but that would be $20 or so. What is my best option? TIA ___ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
Re: Cheap Gigabit switch will allow DHCP thru it?
On Dec 30, 2007 1:16 PM, Bruce Labitt [EMAIL PROTECTED] wrote: Is there a simple way to swap eth0 and eth1? You're running Fedora, right? If so, get to a root shell prompt, and do the following: service network stop cd /etc/sysconfig/network-scripts mv ifcfg-eth0 ifcfg-tmp mv ifcfg-eth1 ifcfg-eth0 mv ifcfg-tmp ifcfg-eth1 # now swap the actual network cables (don't type this line :) ) service network start Unless you've got something referencing the actual network interfaces -- which is unusual, most things use IP addresses -- this should work fine. The one question mark might be the firewall. If needed, you can reconfigure it using the command: system-config-securitylevel -- Ben ___ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
Re: Cheap Gigabit switch will allow DHCP thru it?
Is there a simple way to swap eth0 and eth1?
If your system has udev you might find a file with a name
something like /etc/udev/rules.d/z25_persistent-net.rules that
has entries something like this:
SUBSYSTEM==net, DRIVERS==?*, ATTR{address}==00:12:3f:57:4a:66,
NAME=eth0
...which can force the NIC with the specified MAC addr to be
assigned the specified interface name. Just be sure that if
you arrange for an interface to get a new name you also ensure
that all config files that refer to that interface by the old
name are changed to reflect the new name.
___
gnhlug-discuss mailing list
gnhlug-discuss@mail.gnhlug.org
http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
Re: Cheap Gigabit switch will allow DHCP thru it?
Ben Scott wrote: On Dec 30, 2007 1:16 PM, Bruce Labitt [EMAIL PROTECTED] wrote: Is there a simple way to swap eth0 and eth1? You're running Fedora, right? If so, get to a root shell prompt, and do the following: service network stop cd /etc/sysconfig/network-scripts mv ifcfg-eth0 ifcfg-tmp mv ifcfg-eth1 ifcfg-eth0 mv ifcfg-tmp ifcfg-eth1 # now swap the actual network cables (don't type this line :) ) service network start Unless you've got something referencing the actual network interfaces -- which is unusual, most things use IP addresses -- this should work fine. The one question mark might be the firewall. If needed, you can reconfigure it using the command: system-config-securitylevel You will also need to edit the ifcfg-eth0 and ifcfg-eth1 files to actually say DEVICE=eth0 and DEVICE=eth1 respectively. Since udev is on by default (at least in FC8), you will need to edit /etc/udev/... (Mike ODonnell mentioned this in another post). You may also find /etc/modules.conf needs editing. I do a grep -r eth0 /etc/* to find all the relevant places when I need to do this sort of thing. begin:vcard fn:Dan Jenkins n:Jenkins;Dan org:Rastech Inc. adr:;;21 Curtis Lane;Bedford;NH;03110;USA email;internet:[EMAIL PROTECTED] title:Technical Director tel;work:1-603-206-9951 x-mozilla-html:FALSE version:2.1 end:vcard ___ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
Re: Cheap Gigabit switch will allow DHCP thru it?
On Dec 30, 2007 2:24 PM, Dan Jenkins [EMAIL PROTECTED] wrote: You will also need to edit the ifcfg-eth0 and ifcfg-eth1 files to actually say DEVICE=eth0 and DEVICE=eth1 respectively. D'oh! You're right. I always forget that. Since udev is on by default (at least in FC8), you will need to edit /etc/udev/... Not if if you're swapping the IP configurations, as described above. In that case, the device names should stay the same. Alternatively, you can swap the device names, and keep the IP configuration untouched. Swapping both will end up doing nothing. You may also find /etc/modules.conf needs editing. Only if changing device names, and not the assigned IP configurations. I do a grep -r eth0 /etc/* to find all the relevant places when I need to do this sort of thing. That's a good idea. -- Ben ___ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
Re: Cheap Gigabit switch will allow DHCP thru it?
Ben Scott wrote: On Dec 30, 2007 2:24 PM, Dan Jenkins [EMAIL PROTECTED] wrote: You will also need to edit the ifcfg-eth0 and ifcfg-eth1 files to actually say DEVICE=eth0 and DEVICE=eth1 respectively. D'oh! You're right. I always forget that. As have I, which is why I remember it now. Since udev is on by default (at least in FC8), you will need to edit /etc/udev/... Not if if you're swapping the IP configurations, as described above. In that case, the device names should stay the same. Alternatively, you can swap the device names, and keep the IP configuration untouched. Swapping both will end up doing nothing You may also find /etc/modules.conf needs editing. Only if changing device names, and not the assigned IP configurations. Good point. I had forgotten the original reason. (Not good when answering questions.) I'm usually swapping them from another reason. begin:vcard fn:Dan Jenkins n:Jenkins;Dan org:Rastech Inc. adr:;;21 Curtis Lane;Bedford;NH;03110;USA email;internet:[EMAIL PROTECTED] title:Technical Director tel;work:1-603-206-9951 x-mozilla-html:FALSE version:2.1 end:vcard ___ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
Re: Cheap Gigabit switch will allow DHCP thru it?
On Sunday 30 December 2007 01:49:39 pm Ben Scott wrote: On Dec 30, 2007 1:16 PM, Bruce Labitt [EMAIL PROTECTED] wrote: Is there a simple way to swap eth0 and eth1? You're running Fedora, right? If so, get to a root shell prompt, and do the following: service network stop cd /etc/sysconfig/network-scripts mv ifcfg-eth0 ifcfg-tmp mv ifcfg-eth1 ifcfg-eth0 mv ifcfg-tmp ifcfg-eth1 # now swap the actual network cables (don't type this line :) ) service network start You also need to change the DEVICE= line in ifcfg-eth0 and ifcfg-eth1 to match, and for good measure, should update /etc/modprobe.conf as well to alias the right module to the device. -- Jarod Wilson [EMAIL PROTECTED] ___ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
Re: Cheap Gigabit switch will allow DHCP thru it?
On Dec 30, 2007 7:15 PM, Jarod Wilson [EMAIL PROTECTED] wrote: You also need to change the DEVICE= line in ifcfg-eth0 and ifcfg-eth1 to match, and for good measure, should update /etc/modprobe.conf as well to alias the right module to the device. You won't need to modify /etc/modprobe.conf if you're only swapping IP configurations between logical devices. And swapping both will cancel-out the config changes. Bruce currently has something like the following: SOHO router = onboard, named eth0, configured as 192.168.1.0/24, default gateway HDHomeRun = card, named eth1, configured as 10.0.0.0/24 He wants swap the devices connected to the NICs. That's a physical change, and is the whole point of this. :) So after the cable swap, we have this: HDHomeRun = onboard, named eth0, configured as 192.168.1.0/24, default gateway SOHO router = card, named eth1, configured as 10.0.0.0/24 Now the problem is, his system will still be trying to talk to the Internet using the cable that's plugged into his tuner, and MythTV will be trying to find the tuner where the router is. That won't work at all. My suggestion (modulo the forgotten config edit) is swap the configuration being applied to the logical device names. The result would be: HDHomeRun = onboard, named eth0, configured as 10.0.0.0/24 SOHO router = card, named eth1, configured as 192.168.1.0/24, default gateway The other approach, originally suggested by MOD, would be to swap the names the kernel is assigning to the devices: SOHO router = onboard, named eth1, configured as 192.168.1.0/24, default gateway HDHomeRun = card, named eth0, configured as 10.0.0.0/24 Thinking about it, I actually like the later method better, as it bypasses any firewall/DHCP/etc config file changes to update devices. You just change what each device is being called. -- Ben ___ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
Re: Cheap Gigabit switch will allow DHCP thru it?
On Sunday 30 December 2007 07:50:55 pm Ben Scott wrote: On Dec 30, 2007 7:15 PM, Jarod Wilson [EMAIL PROTECTED] wrote: You also need to change the DEVICE= line in ifcfg-eth0 and ifcfg-eth1 to match, and for good measure, should update /etc/modprobe.conf as well to alias the right module to the device. You won't need to modify /etc/modprobe.conf if you're only swapping IP configurations between logical devices. And swapping both will cancel-out the config changes. If only swapping IP configs, sure. If also changing devices, still not actually necessary, as the network bring-up scripts actually handle renaming devices as needed to match the ifcfg-ethX files, but still recommended for consistency. -- Jarod Wilson [EMAIL PROTECTED] ___ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
Cheap Gigabit switch will allow DHCP thru it?
I'm looking to add another hdhomerun tunerbox to my myth setup. I have a DHCP server running to give the existing tuner its IP address. Can I add a cheap gigabit switch to add the other tuner? Will the requests for IP address be routed to the server properly? How do I guarantee the tuners don't swap if the power goes down? Does it matter? ___ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
Re: Cheap Gigabit switch will allow DHCP thru it?
On Dec 29, 2007 12:31 PM, Bruce Labitt [EMAIL PROTECTED] wrote: I'm looking to add another hdhomerun tunerbox to my myth setup. I have a DHCP server running to give the existing tuner its IP address. Can I add a cheap gigabit switch to add the other tuner? Will the requests for IP address be routed to the server properly? Short answer: Buy the switch and it will likely just work. If it doesn't just work, it will be a simple matter to make it just work -- just ask here. Longer answer: A switch is what is called a layer 2 device; all it does is forward Ethernet frames. IP, DHCP, and friends are all layer 3 or higher. So DHCP and everything else will not even be aware that the switch is there. It's all one, big happy Ethernet network. That means that the DHCP server, and your HDHRs, will all appear to be peers to each other. So DHCP will flow just fine, but there will also be no way for any of the devices to tell how they are physically connected (i.e., they don't know there is a switch involved, or what port of the switch they are plugged into). All that said, every Ethernet device has an address (sometimes called a MAC address) which uniquely identifies the device. So each HDHR has a unique Ethernet address. The DHCP server will be aware of that address, and can potentially use it to assign a specific IP address to each one. What the right thing to do is depends on how MythTV finds the HDHRs. I seem to recall that MythTV uses a broadcast packet to find the HDHRs. If that is the case, the IP address of the HDHR won't matter -- the broadcast packet will reach both of them, and MythTV will have to tell them apart. -- Ben ___ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
Re: Cheap Gigabit switch will allow DHCP thru it?
On Saturday 29 December 2007 01:01:06 pm Ben Scott wrote: On Dec 29, 2007 12:31 PM, Bruce Labitt [EMAIL PROTECTED] wrote: I'm looking to add another hdhomerun tunerbox to my myth setup. I have a DHCP server running to give the existing tuner its IP address. Can I add a cheap gigabit switch to add the other tuner? [...] What the right thing to do is depends on how MythTV finds the HDHRs. I seem to recall that MythTV uses a broadcast packet to find the HDHRs. If that is the case, the IP address of the HDHR won't matter -- the broadcast packet will reach both of them, and MythTV will have to tell them apart. You can have mythtv find and hdhr a few different ways. If you only have one on your network, you can just throw in a broadcast mac address of . If you've got more than one, you need to either specify them by ip address or actual mac address. If you're worried that their ip addresses will change, just use their mac addresses. (mythtv 0.20.x may only work with mac addresses anyway, can't recall when the ip-based option was added). -- Jarod Wilson [EMAIL PROTECTED] ___ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
Re: Cheap Gigabit switch will allow DHCP thru it?
Ben Scott [EMAIL PROTECTED] writes: On Dec 29, 2007 12:31 PM, Bruce Labitt [EMAIL PROTECTED] wrote: I'm looking to add another hdhomerun tunerbox to my myth setup. I have a DHCP server running to give the existing tuner its IP address. Can I add a cheap gigabit switch to add the other tuner? Will the requests for IP address be routed to the server properly? Short answer: Buy the switch and it will likely just work. If it doesn't just work, it will be a simple matter to make it just work -- just ask here. Longer answer: A switch is what is called a layer 2 device; all it does is forward Ethernet frames. IP, DHCP, and friends are all layer 3 or higher. So DHCP and everything else will not even be aware that the switch is there. It's all one, big happy Ethernet network. If memory serves (though, often times, sadly, it serves incorrectly :) DHCP is heavily dependant upon (r)ARP (specifically when combined with PXE), which kinda sorta sits in a no-where land between layers 2 and 3 (like ICMP). That being said, it's also heavily dependant on UDP broadcasts (DHCP_DISCOVER and DHC_PREQUEST), which should also traverse switches just fine. I seem to recall that MythTV uses a broadcast packet to find the HDHRs. If that is the case, the IP address of the HDHR won't matter -- the broadcast packet will reach both of them, and MythTV will have to tell them apart. If that's the case, then the switch shouldn't interfere at all... -- Seeya, Paul ___ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
Re: Cheap Gigabit switch will allow DHCP thru it?
On Dec 29, 2007 12:31 PM, Bruce Labitt [EMAIL PROTECTED] wrote: I'm looking to add another hdhomerun tunerbox to my myth setup. I have a DHCP server running to give the existing tuner its IP address. Can I add a cheap gigabit switch to add the other tuner? Will the requests for IP address be routed to the server properly? I have a cheap netgear gigabit switch and all the devices do dhcp that are connected on it. -- Jeff Macdonald Ayer, MA ___ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
