Re: ipforward'ing on in kernel?
At 06:56 PM 5/29/98 +0200, Nils Rennebarth wrote: >> I thought we could tell by "cat /proc/ksyms | grep forward" : >> 00140988 ip_forward_R35268aee >> 0022ae04 sysctl_ip_forward_Ra7d20d83 >> >> Is this correct? seems to say yes; or do we have to rebuild a new kernel. >No, it is not. You do need a custom kernel. > >N.B: I do not know, why the above symbols are in /proc/ksyms. They are >present in mine also, although I know I do not have ip forwarding enabled. >Does anyone know a better test? -- I thought that this indicated that it was copmiled into the kernel, a different issue than if the feature is (run-time) enabled. Thanks. Dr. Gregory Guthrie [EMAIL PROTECTED] (515)472-1125Fax: -1103 Computer Science Department College of Science and Technology Maharishi University of Management (Maharishi International University 1971-1995) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: ipforward'ing on in kernel?
On Fri, May 29, 1998 at 10:49:33AM -0500, Gregory Guthrie wrote: > The basic question is: is IP-forwarding on in the default kernel No. > , and how does one tell look at /boot/config-, included in every kernel-image-xxx package of debian. (N.B. This inlcudes kernel-image-xxx packages you build yourself when using make-kpkg, which is one of many reasons to use this package to build your custom kernel) > or does one have to build a custom kernel to do routing? Yes. You should do that for routers anyway. There are so much possibilities and tuning to be done if you want to build a router. > -- In gereral, how does one tell if a feature is on in a kernel? That is next to impossible, if you are given a kernel image only. > We want to setup a local simple router-pair, to create a LAN-remote subnet > segment. > > I thought we could tell by "cat /proc/ksyms | grep forward" : > 00140988 ip_forward_R35268aee > 0022ae04 sysctl_ip_forward_Ra7d20d83 > > Is this correct? seems to say yes; or do we have to rebuild a new kernel. No, it is not. You do need a custom kernel. N.B: I do not know, why the above symbols are in /proc/ksyms. They are present in mine also, although I know I do not have ip forwarding enabled. Does anyone know a better test? > "grep FORWARD /usr/src/linux/.config" is the ideal command for this. > CONFIG_IP_FORWARD=y means it is turned ON > # CONFIG_IP_FORWARD is not set means it is turned OFF This still holds for debian, if you replace /usr/src/linux/.config by /boot/config-`uname -r` > What about Debian? > On the CDROM (1.3.1), the .config file says: > -- > ... > # CONFIG_IP_FORWARD is not set > ... > Does this correspond to the binary kernel distributed, or is it just a > standard default spec for building new kernels? it corresponds to the binary kernel distributed. > 4) We also need PPP proxyarp, is it on by default (curious about the ARPD > not set). This is not related to kernel compiling options. ARPD is in case you have a single (non bridged) ethernet with a *lot* (more that 256) of nodes on it. Nils -- *-* | Quotes from the net: L> Linus Torvalds, W> Winfried Truemper | | L>this is the special easter release of linux, more mundanely called 1.3.84 | | W>Umh, oh. What do you mean by "special easter release"?. Will it quit | * W>working today and rise on easter? * pgp6KTTkNx3gr.pgp Description: PGP signature
Re: ipforward'ing on in kernel?
On Fri, 29 May 1998, Gregory Guthrie wrote: > [Since I got no answer last time, I am trying again on this query] > > The basic question is: is IP-forwarding on in the default kernel, and how > does one tell, or does one have to build a custom kernel to do routing? > -- In gereral, how does one tell if a feature is on in a kernel? No it isn't. You need a custom kernel. IMHO everybody needs a custom kernel. The installation ones are bogged down by drivers required to support every known boot device. And you look in .config, if it's been kept. > > Details: > We want to setup a local simple router-pair, to create a LAN-remote subnet > segment. > > 1) To support this, we need routing enabled in the kernel. Does the default > kernel on the 1.3.1 CDROM have this enabled? I doubt it. > [...] > > 4) We also need PPP proxyarp, is it on by default (curious about the ARPD > not set). I don't think there's any connection. I think defaultroute and proxyarp are on in PPP by default, which leads to much mystification when people read messages about them in the logs in circumstances where they're not used. ppp is not built into bo installation kernels, but I guess it might be in more recent ones as I think that's now a supported method of installation. Cheers, -- Email: [EMAIL PROTECTED] Tel: +44 1908 653 739 Fax: +44 1908 655 151 Snail: David Wright, Earth Science Dept., Milton Keynes, England, MK7 6AA Disclaimer: These addresses are only for reaching me, and do not signify official stationery. Views expressed here are either my own or plagiarised. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
ipforward'ing on in kernel?
[Since I got no answer last time, I am trying again on this query] The basic question is: is IP-forwarding on in the default kernel, and how does one tell, or does one have to build a custom kernel to do routing? -- In gereral, how does one tell if a feature is on in a kernel? Details: We want to setup a local simple router-pair, to create a LAN-remote subnet segment. 1) To support this, we need routing enabled in the kernel. Does the default kernel on the 1.3.1 CDROM have this enabled? rrouter# uname -a Linux rrouter 2.0.30 #1 Sun Jun1 09:14:11 EST 1997 i586 rrouter# I thought we could tell by "cat /proc/ksyms | grep forward" : 00140988 ip_forward_R35268aee 0022ae04 sysctl_ip_forward_Ra7d20d83 Is this correct? seems to say yes; or do we have to rebuild a new kernel. 2) How do we tell what options are compiled into the Kernel? 3) I read: "The Slackware Linux kernel as shipped does NOT have IP FORWARDING enabled. So you can hook it up to the net, and use Linux directly on the net, but Linux won't pass packets through to your local Ethernet or what have you. There is no way to tell from the boot messages that this feature is on or off. The only way is to look at the config file for building the kernel in /usr/src/linux/.config and see what CONFIG_IP_FORWARD is set to. "grep FORWARD /usr/src/linux/.config" is the ideal command for this. CONFIG_IP_FORWARD=y means it is turned ON # CONFIG_IP_FORWARD is not set means it is turned OFF The only way to enable this feature is to rebuild the kernel. What about Debian? On the CDROM (1.3.1), the .config file says: -- # # Networking options # # CONFIG_FIREWALL is not set # CONFIG_NET_ALIAS is not set CONFIG_INET=y # CONFIG_IP_FORWARD is not set # CONFIG_IP_MULTICAST is not set CONFIG_SYN_COOKIES=y CONFIG_RST_COOKIES=y # CONFIG_IP_ACCT is not set # CONFIG_IP_ROUTER is not set # CONFIG_NET_IPIP is not set # CONFIG_ARPD is not set Does this correspond to the binary kernel distributed, or is it just a standard default spec for building new kernels? 4) We also need PPP proxyarp, is it on by default (curious about the ARPD not set). Thanks, Greg -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: ipforward'ing on in kernel?
Gregory Guthrie wrote: > 2) How do we tell what options are compiled into the Kernel? What if you just try giving ipfwadm commands to see if they're accepted or not? -- ...RickM... -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
ipforward'ing on in kernel?
We want to setup a local simple router-pair, to create a LAN-remote subnet segment. 1) To support this, we need routing enabled in the kernel. Does the default kernel on the 1.3.1 CDROM have this enabled? rrouter# uname -a Linux rrouter 2.0.30 #1 Sun Jun1 09:14:11 EST 1997 i586 rrouter# I thought we could tell by "cat /proc/ksyms | grep forward" : 00140988 ip_forward_R35268aee 0022ae04 sysctl_ip_forward_Ra7d20d83 Is this correct? seems to say yes; or do we have to rebuild a new kernel. 2) How do we tell what options are compiled into the Kernel? 3) I read: "The Slackware Linux kernel as shipped does NOT have IP FORWARDING enabled. So you can hook it up to the net, and use Linux directly on the net, but Linux won't pass packets through to your local Ethernet or what have you. There is no way to tell from the boot messages that this feature is on or off. The only way is to look at the config file for building the kernel in /usr/src/linux/.config and see what CONFIG_IP_FORWARD is set to. "grep FORWARD /usr/src/linux/.config" is the ideal command for this. CONFIG_IP_FORWARD=y means it is turned ON # CONFIG_IP_FORWARD is not set means it is turned OFF The only way to enable this feature is to rebuild the kernel. What about Debian? On the CDROM (1.3.1), the .config file says: -- # # Networking options # # CONFIG_FIREWALL is not set # CONFIG_NET_ALIAS is not set CONFIG_INET=y # CONFIG_IP_FORWARD is not set # CONFIG_IP_MULTICAST is not set CONFIG_SYN_COOKIES=y CONFIG_RST_COOKIES=y # CONFIG_IP_ACCT is not set # CONFIG_IP_ROUTER is not set # CONFIG_NET_IPIP is not set # CONFIG_ARPD is not set Does this correspond to the binary kernel distributed, or is it just a standard default spec for building new kernels? 4) We also need PPP procxyarp, is it on by default (curious about the ARPD not set). Thanks, Greg Dr. Gregory Guthrie [EMAIL PROTECTED] (515)472-1125Fax: -1103 Computer Science Department College of Science and Technology Maharishi University of Management (Maharishi International University 1971-1995) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
