X-Git-Url: http://git.grml.org/?a=blobdiff_plain;f=grml_tips;h=a355ac2fe3feea97c2a265aa2c1f3e0f2b7bf529;hb=fec2f722c92f4b2a5ed90bc7a9ac705da5f361e1;hp=ce981763b0c7d786250596d8c71a80d41aa88981;hpb=7c8c9ce28c299033a71a4a6090885dd51fae48ea;p=grml-tips.git diff --git a/grml_tips b/grml_tips index ce98176..a355ac2 100644 --- a/grml_tips +++ b/grml_tips @@ -2630,6 +2630,152 @@ any further work. -- Debugging SSL communications: -% openssl s_client -connect webmail.grml.org:993 +% openssl s_client -connect server.adress:993 + +or # ssldump -a -A -H -i eth0 + +See http://prefetch.net/articles/debuggingssl.html for more details. +-- +Remove bootmanager from MBR: + +# lilo -M /dev/hda -s /dev/null +-- +Rewrite grub to MBR: + +# mount /mnt/sda1 +# grub-install --recheck --no-floppy --root-directory=/mnt/sda1 /dev/sda +-- +Rewrite lilo to MBR: + +# mount /mnt/hda1 +# lilo -r /mnt/hda1 +-- +Create screenshot of plain/real console - tty1: + +# fbgrab -c 1 screeni.png +-- +Create screenshot when running X: + +% scrot + +Tip: use the gkrellshoot plugin when using gkrellm +-- +Redirect all connections to hostA:portA to hostB:portB, where hostA and hostB are +different networks: + +Run the following commands on hostA: + +echo 1 > /proc/sys/net/ipv4/ip_forward +iptables -t nat -A PREROUTING -p tcp --dport portA -j DNAT --to hostB:portB +iptables -A FORWARD -i eth0 -o eth0 -d hostB -p tcp --dport portB -j ACCEPT +iptables -A FORWARD -i eth0 -o eth0 -s hostB -p tcp --sport portB -j ACCEPT +iptables -t nat -A POSTROUTING -p tcp -d hostB --dport portB -j SNAT --to-source hostA +-- +Flash BIOS without DOS/Windows: + +Dump flash info and set the flash chip to writable: +# flashrom + +Backup the original BIOS: +# flashrom -r backup.bin + +Notice: the following step will overwrite your current BIOS! +So make sure you really know what you are doing. + +Flash the BIOS image: +# flashrom -wv newbios.bin + +Also check out LinuxBIOS: http://linuxbios.org/ +-- +Enable shadow passwords: + +# shadowconfig on +-- +Set up an IPv6 tunneln on grml: + +# ipv6-tunnel start +-- +Set up console newsreader slrn for use with Usenet: + +% grml-slrn +-- +Calculate with IPv6 addresses: + +% ipv6calc + +For usage examples refer to manpage ipv6calc(8). +-- +Common network debugging tools for use with IPv6: + +% ping6 +% tracepath6 +% traceroute6 +% tracert6 +% nc6 +% tcpspray6 +-- +Set up NFS (Network File System): + +Server-side +~~~~~~~~~~~ +Make sure the relevant services are running on the server side: + +# /etc/init.d/portmap start +# /etc/init.d/nfs-common start +# /etc/init.d/nfs-kernel-server start + +Export shares via /etc/exports: + +/backups 192.168.1.100/24(rw,wdelay,no_root_squash,async,subtree_check) + +... or manually export a directory running: + +# exportfs -o rw,wdelay,no_root_squash,async,subtree_check 192.168.1.100:/backups + +and unexport a share running: + +# exportfs -u 192.168.1.100:/backups + +and every time when you modify /etc/exports file run + +# exportfs -ra + +Display what NFS components are running: + +# rpcinfo -p + +Display list of exported shares: + +# exportfs -v +or +# showmount -e + +Client-side +~~~~~~~~~~~ +Make sure the relevant services are running on the client side: + +# /etc/init.d/portmap start +# /etc/init.d/nfs-common start + +Verify that the server allows you to access its RPC/NFS services: + +# rpcinfo -p server_name + +Check what directories the server exports: + +# showmount -e server_name + +On the client side you can use something like the following in /etc/fstab: + +192.168.1.101:/backups /mnt/nfs nfs defaults,users,wsize=8192,rsize=8192 0 0 +-- +Mount a cloop file: + +# aptitude install cloop-src +# m-a a-i cloop-src + +# modprobe cloop file=/path/to/cloop/file +# mount -r -t iso9660 /dev/cloop /mnt/test +--