opkg update无法更新怎么办，源改过了

for***

头都要炸了。。。
运行opkg update，总是失败，还望大神指点！！！我用的是校园网（openwrt+mentohust),但总是提示
root@OpenWrt:~# opkg update
Downloading https://downloads.openwrt.org/ba ... /base//Packages.gz.
Downloading https://downloads.openwrt.org/ba ... /luci//Packages.gz.
Downloading https://downloads.openwrt.org/ba ... kages//Packages.gz.
Downloading https://downloads.openwrt.org/ba ... kages//Packages.gz.
Downloading https://downloads.openwrt.org/ba ... uting//Packages.gz.
Collected errors:
* opkg_download: Failed to download https://downloads.openwrt.org/ba ... s/base//Packages.gz, wget returned 5.
* opkg_download: Failed to download https://downloads.openwrt.org/ba ... s/luci//Packages.gz, wget returned 5.
* opkg_download: Failed to download https://downloads.openwrt.org/ba ... ckages//Packages.gz, wget returned 5.
* opkg_download: Failed to download https://downloads.openwrt.org/ba ... ckages//Packages.gz, wget returned 5.
* opkg_download: Failed to download https://downloads.openwrt.org/ba ... outing//Packages.gz, wget returned 5.

for***

求大神，帮忙解决！！！

jero***

下载下来本地服务器升级就好了