I intend to download GeoIp from http://pkgs.org/download/geoip
But I don't know which distribution should I choose because there is no download link for Scientific Linux 4.0.

Can I use the package of other Linux distribution for Scientific Linux 4.0?

As far as I know SL is based on RHEL,
so you can try CentOS RpmForge rpm packages like (be sure to select i386 or x86_64 version according to your system: #uname -a ):

# rpm --test -Uvh http://apt.sw.be/redhat/el5/en/i386/...l5.rf.i386.rpm

and if it outputs :
Preparing... ########################################### [100%]
#

without any "dependency missing errors" you're safe to install it:
# rpm -Uvh http://apt.sw.be/redhat/el5/en/i386/...l5.rf.i386.rpm

PS: sorry, I read it now you have SL 4 so go for CentOS 4 (RHEL 4) versions from RPMforge

SL 4 - Since SLC/SL are based on sources of Red Hat Enterprise Linux 4 (RHEL4) sources ...

http://pkgs.org/download/geoip >>> Look for 'CentOS 4 (RHEL 4)'

Those packages are for Scientific Linux SL4 too :
GeoIP-1.4.8-1.el4.i386.rpm GeoIP-1.4.8-1.el4.x86_64.rpm

# yum install GeoIP : Just add the EPEL.repo https://fedoraproject.org/wiki/EPEL

http://download.fedoraproject.org/pu...-10.noarch.rpm
→ → # rpm -Uvh epel-release-4-10.noarch.rpm

.

is there a MUST USE reason for needing sl( rhel/cent) 4.9
4.9 is the ONLY supported version for sl4

sl4 is getting close to it's end of life, so unless you MUST USE IT ,
it's time to upgrade and install the current SL6.1 .

for the three
RHEL4
CentOS4
SL4

the el4 repos are used
el5 and el6 for rhel5 & 6

BUT BE WARNED ( yes bold) most repos for el4 and 5 are incompatible with other ones

now assuming you installed yum on sl4 ( was NOT installed in 4 - it did not yet exist rhel4 used "up2date" )

there are yum plugins needed so you DO NOT kill the install
"yum-protectbase" and "yum-priorities"