FEDORA version differences

FEDORA version differences

The book primarily covers the latest versions of Fedora Linux, but many systems

administrators still use older versions. This appendix lists a number of

features in configuration files and quirks in the operation of some of the older

versions of Fedora/Red Hat Linux.

FTP DIFFERENCES

There are some well known differences in the configuration of the VSFTP

package for version 8.0 and earlier of Red Hat/Fedora Linux.

For one, the starting and stopping of VSFTP is controlled by xinetd via

the /etc/xinetd.d/vsftpd file. VSFTP is deactivated by default, so you'll have

to edit this file to start the program. Make sure the contents look like the

example. The disable feature must be set to no to accept connections.

service ftp

Linux will automatically edit this file to enable VSFTPD and restart

xinetd with the chkconfig command.

[root@bigboy tmp]# chkconfig vsftpd on

[root@bigboy tmp]#

Naturally, to disable VSFTP once again, you'll use the chkconfig vsftpd

off command.

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DHCP DIFFERENCES

There can be problems when upgrading from Red Hat 7.3 to 8.0 while maintaining the same dhcpd.conf file. You might run into a DHCP server error. This startup error is caused by not having this line at the very top of your /etc/dhcpd.conf file:

ddns-update-style interim

The error might look like:

Starting dhcpd: Internet Software Consortium DHCP Server V3.0pl1

Copyright 1995-2001 Internet Software Consortium.

All rights reserved.

For info, please visit https://www.isc.org/products/DHCP

** You must add a ddns-update-style statement to /etc/dhcpd.conf.

To get the same behaviour as in 3.0b2pl11 and previous

versions, add a line that says "ddns-update-style ad-hoc;"

Please read the dhcpd.conf manual page for more information. **

exiting.

[FAILED]

DNS DIFFERENCES

You'll notice some differences running BIND on older versions of Red Hat/Fedora Linux. For example, Red Hat 9 doesn't shutdown BIND cleanly

and gives a "named: already running" error when you try to restart it:

[root@bigboy tmp]# /etc/init.d/named restart

Stopping named:

named: already running[root@bigboy tmp]#

The pkill command enables you to kill processes by referring to them by name instead of their process ID number. In this case, you can forcefully stop the named daemon and restart it by issuing the command pkill named followed by /etc/init.d/named start.

[root@bigboy tmp]# pkill named

pkill: 29988 - No such process

pkill: 29992 - No such process

[root@bigboy tmp]# /etc/init.d/named start

[root@bigboy tmp]#

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ROUTING DIFFERENCES

Some of the older versions of the Fedora stream of Linux had different methods

of updating their routes. For example, in Red Hat versions 8 and 9, the file

named /etc/sysconfig/static-routes was used to add permanent static routes

that would be present after a reboot. The format is similar to that of the route

command except that the interface comes first and the switches have no

dashes in front of them. Here is a sample entry for a route to 10.0.0.0 via the

192.168.1.254 gateway:

wlan0 net 10.0.0.0 netmask 255.0.0.0 gw 192.168.1.254

The /etc/sysconfig/static-routes file is set to be deprecated in future

releases, and you should consider the alternative solutions for newer operating

systems.

IPTABLES DIFFERENCES

In Red Hat/Fedora 9 and earlier, iptables gave a different status message

when the firewall was stopped. Instead of saying stopped, it presented a rule

set that allowed all traffic through.

[root@bigboy tmp]# service iptables status

Table: filter

Chain INPUT (policy ACCEPT)

target prot opt source destination

Chain FORWARD (policy ACCEPT)

target prot opt source destination

Chain OUTPUT (policy ACCEPT)

target prot opt source destination

[root@bigboy tmp]#

SOFTWARE INSTALLATION DIFFERENCES

With some older Red Hat Linux versions, source RPM files are first exported

into the directory /usr/src/redhat/SPECS with the rpm command. You then have

to run the rpm command again to compile the source files into a regular RPM

file, which will be placed in either the /usr/src/packages/RPMS/i386/ or the

/usr/src/redhat/RPMS/i386/ directories. You then have to install the new RPM

file from this directory.

Software Installation Differences 619

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[root@bigboy tmp]# rpm -Uvh filename.src.rpm

[root@bigboy tmp]# cd /usr/src/redhat/SPECS

[root@bigboy SPECS]# rpm -ba filename

[root@bigboy SPECS]# cd /usr/src/redhat/RPM/i386

[root@bigboy i386]# rpm -Uvh filename.rpm

WIRELESS NETWORKING DIFFERENCES

Under version 8.0 of Red Hat I have seen the kernel-wlan-ng-pcmcia RPM

installation give errors stating that the kernel-pcmcia-cs RPM hadn't been

previously installed even when it had been. Installing the RPM with --force

and --nodeps switches does the trick by forcing the installation while not

checking for dependencies. Always remember that under normal circumstances

this wouldn't be a good idea, error messages are there for a reason.

[root@bigboy tmp]# rpm -Uvh kernel-wlan-ng-pcmcia-0.1.15-6.i686.rpm

error: Failed dependencies:

kernel-pcmcia-cs is needed by kernel-wlan-ng-pcmcia-0.1.15-6

[root@bigboy tmp]# rpm -Uvh --force --nodeps kernel-wlan-ng-pcmcia-

0.1.15-6.i686.rpm

Preparing ################################## [100%]

1:kernel-wlan-ng-pcmcia ################################## [100%]

Adding prism2_cs alias to /etc/modules.conf file

Shutting down PCMCIA services: cardmgr modules.

Starting PCMCIA services: modules cardmgr.

The default wlan0 network configuration is DHCP. Adjust accordingly.

ACHTUNG! ATTENTION! WARNING!

YOU MUST configure /etc/pcmcia/wlan-ng.opts to match WAP settings!!!

[root@bigboy tmp]#

Linux-WLAN File Locations Using Red Hat 8.0 RPMs

The main Linux-WLAN configuration file for version 8.0 is the /etc/wlan.conf

file (PCI type NIC) or your /etc/pcmcia/wlan-ng.opts (PCMCIA type NICs)

configuration file. Locate the lines containing ssid=linux_wlan, and set the

SSID to whatever value you've decided to use on your wireless LAN. This

example uses homenet.

Also modify the IS_ADHOC option to make your NIC either support Ad-hoc

mode for peer-to-peer networks or Infrastructure mode if you are using a WAP.

Here is a sample snippet:

#=======SELECT STATION MODE===================

IS_ADHOC=n # y|n, y - adhoc, n - infrastructure

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#=======INFRASTRUCTURE STATION START===================

# SSID is all we have for now

AuthType="opensystem" # opensystem | sharedkey (requires WEP)

# Use DesiredSSID="" to associate with any AP in range

DesiredSSID="homenet"

MRTG DIFFERENCES

You will need to take the several differences into account when configuring

MRTG for various versions of Fedora and Red Hat.

File Locations

In Red Hat 9 and older, MRTG files are located in the /var/www/html/mrtg/. In

Fedora Core, the files are located in the /var/www/mrtg/ directory. In both cases,

the MRTG graphs can be accessed using a default Apache installation via the

URL https://server-ip-address/mrtg.

indexmaker MRTG_LIB Errors with Red Hat 9 and 8.0

Red Hat versions 8 and 9 give an error when running indexmaker:

[root@bigboy mrtg]# indexmaker --output=index.html

/etc/mrtg/mrtg.cfg

Can't locate package $VERSION for @MRTG_lib::ISA at

/usr/bin/indexmaker line 49

main::BEGIN() called at /usr/bin/../lib/mrtg2/MRTG_lib.pm line 49

eval called at /usr/bin/../lib/mrtg2/MRTG_lib.pm line 49

[root@bigboy mrtg]#

This is caused by an incompatibility between MRTG and PERL 5.8,

which MRTG uses to generate files. The MRTG site claims this was fixed in

version 2.9.22, but this version of MRTG seems to fail under Red Hat.

The fix is simple: Edit the file /usr/lib/mrtg2/MRTG_lib.pm, replacing the

line:

@ISA = qw(Exporter $VERSION);

with:

@ISA = qw(Exporter);

You'll then have to run indexmaker again.

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Precedence Bitwise Error with Red Hat 9

indexmaker may also give an error related to a bitwise operation. It doesn't

seem to affect the operation of MRTG or the HTML index page output. For

example:

Possible precedence problem on bitwise | operator at

/usr/bin/../lib/mrtg2/BER.pm line 601

WEBALIZER DIFFERENCES

Older versions of Webalizer, especially those found with Red Hat 8.0 and earlier,

have a tendency to create this message in your logs:

Error: Unable to open DNS cache file /var/lib/webalizer/dns_cache.db

According to the documentation on Webalizer's Web site, this is not a critical

error. You can make the software run in quiet mode by editing the configuration

file and changing the Quiet parameter to yes:

Quiet yes