Cannot find a valid baseurl for repo: base/7/x86_64

我先是遇到这个问题

<pre name="code" class="html"># yum update
>snip normal startup stuff, then:

Error Downloading Packages:

hmaccalc-0.9.6-4.el5.x86_64: failure: RPMS.fastrack/hmaccalc-0.9.6-4.el5.x86_64.rpm from Int-dev-reporhel5: 

[Errno 256] No more mirrors to try.

acpid-1.0.4-12.el5.x86_64: failure: RPMS.fastrack/acpid-1.0.4-12.el5.x86_64.rpm from Int-dev-reporhel5:

[Errno 256] No more mirrors to try.

1:smartmontools-5.38-3.el5.x86_64: failure: RPMS.fastrack/smartmontools-5.38-3.el5.x86_64.rpm from Int-dev-reporhel5: 

[Errno 256] No more mirrors to try.

evince-0.6.0-17.el5.x86_64: failure: RPMS.fastrack/evince-0.6.0-17.el5.x86_64.rpm from Int-dev-reporhel5: 

[Errno 256] No more mirrors to try.

facter-1.6.6-1.el5.x86_64: failure: RPMS.epel5/facter-1.6.6-1.el5.x86_64.rpm from Int-dev-repoepel5: 

[Errno 256] No more mirrors to try.

# yum clean all
# yum update
Modules complementaires charges : fastestmirror
One of the configured repositories failed (Inconnu), and yum doesn't have enough cached data to continue.
At this point the only safe thing yum can do is fail.
There are a few ways to work "fix" this:
1. Contact the upstream for the repository and get them to fix the problem.
2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream.
This is most often useful if you are using a newer distribution release than is supported by the repository
(and the packages for the previous distribution release still work).
3. Disable the repository, so yum won't use it by default.
Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage:
yum-config-manager --disable <repoid> 4. Configure the failing repository to be skipped,
if it is unavailable. Note that yum will try to contact the repo. when it runs most commands,
so will have to try and fail each time (and thus. yum will be be much slower).
If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true
Cannot find a valid baseurl for repo: base/7/x86_64

解决办法：<span style="color: rgb(34, 36, 38); font-family: Arial, 'Helvetica Neue', Helvetica, sans-serif; font-size: 15px; line-height: 19.5px; background-color: rgb(230, 236, 249);">通过键入＃dhclient的问题解决了</span>