情況是這樣:
最近用16.04 Beta2(xubuntu.mate)及ubuntu16.04重灌多次...
然後adsl設定如版上有教的方式，
然後更新、重開機....一切都ok,

但是

當我選用「升級」之後...(特別有注意到 NetworkManager這也在升級項目中)

再開機，NetworkManager顯示已連線了，但

firefox連不上線了，只google的chrome能用，且
有些網站能連上有的則不能，Youtube, FB連得上，但有些就完全沒動靜，
比如Yahoo' Ubuntu正體中文站都連不上。

再用sudo pppoeconf 設定
firefox...就又連線正常了。

所以只會用的我，猜，是不是NetworkManager這元件出了什麼問題?
可有什麼方法 讓NetworkManager保持不動而升級(由Beta升級至正式版)?

Firefox 連不是上網站是否是因為DNS查詢錯誤？

我是用Linux Mint 18，遇到Firefox開特定網站會DNS查詢錯誤的問題，但同樣網域用nslookup都可以查得到。覺得應該是Firefox的問題而不是NetworkManager的問題才對。

這說來有點像靈異事件(令人難以相信，但卻是這樣)
升級前firefox可開啟這畫面，
升級後，得再設定sudo pppoeconf 才進得來這畫面，
這應不是什麼 特定網站 吧?

附件:

---

  Screenshot at 2016-07-21 17:45:30.png (41.11 KB)

adsl在16.04的NetworkManager「沒作用」的情形，
好像不只在ubuntu系統，
在LMDE，甚至可能在Debian都是這樣?
而ubuntu的源頭是Debian?

如果原系統沒預裝pppoeconf的話，
使用adsl的想連上網路的話...是非常艱難的難關

反應這使用情形，是因我不知如何回報這個bug-如果這是個bug的話

備份連結

================================================

## 相關說明

執行

$ man apt-mark


可以找到下面的說明

...略...

PREVENT CHANGES FOR A PACKAGE

hold
hold is used to mark a package as held back, which will prevent the
package from being automatically installed, upgraded or removed.


...略...

## 操作步驟


以下步驟從剛安裝好的16.04來測試的

執行

$ sudo apt-get update

然後執行

$ apt-cache policy network-manager

顯示

network-manager:
Installed: 1.1.93-0ubuntu4
Candidate: 1.2.0-0ubuntu0.16.04.3
Version table:
1.2.0-0ubuntu0.16.04.3 500
500 http://tw.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
*** 1.1.93-0ubuntu4 500
500 http://tw.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
100 /var/lib/dpkg/status

執行下面指令，將「network-manager」這個套件，設定為hold。
（樓主，你一開始要問的，只有這個指令，其他的步驟只是確認。）

$ sudo apt-mark hold network-manager

顯示

network-manager set on hold.

### 確認方法一

執行

$ apt-mark showhold

顯示

network-manager

### 確認方法二


執行

$ dpkg --get-selections | grep hold

顯示

network-manager hold

### 確認方法三

執行

$ grep 'Package: network-manager$' /var/lib/dpkg/status -A 1

顯示

Package: network-manager
Status: hold ok installed

### 確認方法四

執行

$ dpkg -l network-manager

顯示(一般的狀況，應該是「ii」，現在變成「hi」)

Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-=============================-===================-===================-========
hi network-manager 1.1.93-0ubuntu4 amd64 network management framework (daemon and userspace tools)

==================================================

## 更新測試

執行

$ apt-cache policy network-manager

顯示

network-manager:
Installed: 1.1.93-0ubuntu4
Candidate: 1.2.0-0ubuntu0.16.04.3
Version table:
1.2.0-0ubuntu0.16.04.3 500
500 http://tw.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
*** 1.1.93-0ubuntu4 500
500 http://tw.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
100 /var/lib/dpkg/status

執行

$ sudo apt-get install network-manager

顯示

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following held packages will be changed:
network-manager
The following packages will be upgraded:
network-manager
1 upgraded, 0 newly installed, 0 to remove and 275 not upgraded.
Need to get 1949 kB of archives.
After this operation, 12.3 kB of additional disk space will be used.
Do you want to continue? [Y/n]

執行

$ sudo apt-get upgrade

顯示 (注意下面的 The following packages have been kept back:)

Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
linux-generic linux-headers-generic linux-image-generic network-manager
The following packages will be upgraded:
accountsservice adwaita-icon-theme apport apport-gtk appstream apt apt-transport-https apt-utils base-files bash bash-completion bind9-host
binutils brltty brltty-x11 bsdutils command-not-found command-not-found-data console-setup console-setup-linux cpp-5 dh-python
distro-info-data dmidecode dnsmasq-base dnsutils dosfstools dpkg file-roller firefox firefox-locale-en fonts-noto-cjk fonts-opensymbol fuse
fwupd gcc-5 gcc-5-base gdb gdbserver gir1.2-gmenu-3.0 gir1.2-gst-plugins-base-1.0 gir1.2-gstreamer-1.0 gir1.2-gtk-3.0
gir1.2-packagekitglib-1.0 gir1.2-soup-2.4 glib-networking glib-networking-common glib-networking-services gnome-menus gnome-software
gnome-software-common grep grub-common grub-pc grub-pc-bin grub2-common gstreamer1.0-libav gstreamer1.0-plugins-base
gstreamer1.0-plugins-good gstreamer1.0-pulseaudio gstreamer1.0-x gtk2-engines-murrine gvfs gvfs-backends gvfs-bin gvfs-common gvfs-daemons
gvfs-fuse gvfs-libs imagemagick imagemagick-6.q16 imagemagick-common init init-system-helpers initramfs-tools initramfs-tools-bin
initramfs-tools-core isc-dhcp-client isc-dhcp-common keyboard-configuration klibc-utils language-pack-en language-pack-en-base
language-pack-gnome-en language-pack-gnome-en-base language-selector-common language-selector-gnome libaccountsservice0 libappstream-glib8
libappstream3 libapt-inst2.0 libapt-pkg5.0 libarchive13 libasan2 libatomic1 libbind9-140 libblkid1 libboost-date-time1.58.0
libboost-filesystem1.58.0 libboost-iostreams1.58.0 libboost-system1.58.0 libbrlapi0.6 libcc1-0 libcilkrts5 libdfu1 libdns-export162
libdns162 libdpkg-perl libdrm-amdgpu1 libdrm-intel1 libdrm-nouveau2 libdrm-radeon1 libdrm2 libexpat1 libfdisk1 libfuse2 libfwupd1
libgcc-5-dev libgd3 libglib2.0-0 libglib2.0-bin libglib2.0-data libgnome-menu-3-0 libgnutls-openssl27 libgnutls30 libgomp1
libgstreamer-plugins-base1.0-0 libgstreamer-plugins-good1.0-0 libgstreamer1.0-0 libgtk-3-0 libgtk-3-bin libgtk-3-common libimobiledevice6
libisc-export160 libisc160 libisccc140 libisccfg140 libitm1 libklibc libksba8 libldap-2.4-2 liblightdm-gobject-1-0 libllvm3.8 liblsan0
liblwres141 libmagickcore-6.q16-2 libmagickcore-6.q16-2-extra libmagickwand-6.q16-2 libmount1 libmpx0 libndp0 libnm-glib-vpn1 libnm-glib4
libnm-gtk-common libnm-gtk0 libnm-util2 libnm0 libnma-common libnma0 libnspr4 libnss3 libnss3-nssdb libpackagekit-glib2-16 libpam-systemd
libplymouth4 libpurple-bin libpurple0 libpython2.7 libpython2.7-minimal libpython2.7-stdlib libpython3.5 libpython3.5-minimal
libpython3.5-stdlib libquadmath0 libreoffice-base-core libreoffice-calc libreoffice-common libreoffice-core libreoffice-gtk
libreoffice-help-en-us libreoffice-math libreoffice-style-elementary libreoffice-style-galaxy libreoffice-writer libsmartcols1 libsmbclient
libsoup-gnome2.4-1 libsoup2.4-1 libssl1.0.0 libstdc++6 libsystemd0 libtasn1-6 libtevent0 libtsan0 libubsan0 libudev1
libunity-protocol-private0 libunity-scopes-json-def-desktop libunity9 libupower-glib3 libusbmuxd4 libuuid1 libwbclient0 libwhoopsie0
libwnck-common libwnck22 libxml2 lightdm linux-firmware linux-libc-dev lsb-base lsb-release lshw mount mtr-tiny mythes-en-us
network-manager-gnome openssh-client openssl pidgin pidgin-data plymouth plymouth-label plymouth-theme-ubuntu-text printer-driver-brlaser
python2.7 python2.7-minimal python3-apport python3-commandnotfound python3-distupgrade python3-problem-report python3-software-properties
python3-uno python3-urllib3 python3.5 python3.5-minimal samba-libs sbsigntool shared-mime-info snapd software-properties-common
software-properties-gtk sudo systemd systemd-sysv thermald thunderbird thunderbird-locale-en thunderbird-locale-en-us tzdata
ubuntu-core-launcher ubuntu-drivers-common ubuntu-mono ubuntu-release-upgrader-core ubuntu-release-upgrader-gtk udev uno-libs3
update-notifier update-notifier-common upower upstart ure util-linux uuid-runtime vim-common vim-tiny wget whoopsie xbrlapi xinit
xserver-common xserver-xorg-core
272 upgraded, 0 newly installed, 0 to remove and 4 not upgraded.
Need to get 379 MB/386 MB of archives.
After this operation, 33.6 MB of additional disk space will be used.
Do you want to continue? [Y/n]

執行

$ sudo apt-get dist-upgrade

顯示 (注意下面的 The following packages have been kept back:)

Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following NEW packages will be installed:
linux-headers-4.4.0-31 linux-headers-4.4.0-31-generic linux-image-4.4.0-31-generic linux-image-extra-4.4.0-31-generic
The following packages have been kept back:
network-manager
The following packages will be upgraded:
accountsservice adwaita-icon-theme apport apport-gtk appstream apt apt-transport-https apt-utils base-files bash bash-completion bind9-host
binutils brltty brltty-x11 bsdutils command-not-found command-not-found-data console-setup console-setup-linux cpp-5 dh-python
distro-info-data dmidecode dnsmasq-base dnsutils dosfstools dpkg file-roller firefox firefox-locale-en fonts-noto-cjk fonts-opensymbol fuse
fwupd gcc-5 gcc-5-base gdb gdbserver gir1.2-gmenu-3.0 gir1.2-gst-plugins-base-1.0 gir1.2-gstreamer-1.0 gir1.2-gtk-3.0
gir1.2-packagekitglib-1.0 gir1.2-soup-2.4 glib-networking glib-networking-common glib-networking-services gnome-menus gnome-software
gnome-software-common grep grub-common grub-pc grub-pc-bin grub2-common gstreamer1.0-libav gstreamer1.0-plugins-base
gstreamer1.0-plugins-good gstreamer1.0-pulseaudio gstreamer1.0-x gtk2-engines-murrine gvfs gvfs-backends gvfs-bin gvfs-common gvfs-daemons
gvfs-fuse gvfs-libs imagemagick imagemagick-6.q16 imagemagick-common init init-system-helpers initramfs-tools initramfs-tools-bin
initramfs-tools-core isc-dhcp-client isc-dhcp-common keyboard-configuration klibc-utils language-pack-en language-pack-en-base
language-pack-gnome-en language-pack-gnome-en-base language-selector-common language-selector-gnome libaccountsservice0 libappstream-glib8
libappstream3 libapt-inst2.0 libapt-pkg5.0 libarchive13 libasan2 libatomic1 libbind9-140 libblkid1 libboost-date-time1.58.0
libboost-filesystem1.58.0 libboost-iostreams1.58.0 libboost-system1.58.0 libbrlapi0.6 libcc1-0 libcilkrts5 libdfu1 libdns-export162
libdns162 libdpkg-perl libdrm-amdgpu1 libdrm-intel1 libdrm-nouveau2 libdrm-radeon1 libdrm2 libexpat1 libfdisk1 libfuse2 libfwupd1
libgcc-5-dev libgd3 libglib2.0-0 libglib2.0-bin libglib2.0-data libgnome-menu-3-0 libgnutls-openssl27 libgnutls30 libgomp1
libgstreamer-plugins-base1.0-0 libgstreamer-plugins-good1.0-0 libgstreamer1.0-0 libgtk-3-0 libgtk-3-bin libgtk-3-common libimobiledevice6
libisc-export160 libisc160 libisccc140 libisccfg140 libitm1 libklibc libksba8 libldap-2.4-2 liblightdm-gobject-1-0 libllvm3.8 liblsan0
liblwres141 libmagickcore-6.q16-2 libmagickcore-6.q16-2-extra libmagickwand-6.q16-2 libmount1 libmpx0 libndp0 libnm-glib-vpn1 libnm-glib4
libnm-gtk-common libnm-gtk0 libnm-util2 libnm0 libnma-common libnma0 libnspr4 libnss3 libnss3-nssdb libpackagekit-glib2-16 libpam-systemd
libplymouth4 libpurple-bin libpurple0 libpython2.7 libpython2.7-minimal libpython2.7-stdlib libpython3.5 libpython3.5-minimal
libpython3.5-stdlib libquadmath0 libreoffice-base-core libreoffice-calc libreoffice-common libreoffice-core libreoffice-gtk
libreoffice-help-en-us libreoffice-math libreoffice-style-elementary libreoffice-style-galaxy libreoffice-writer libsmartcols1 libsmbclient
libsoup-gnome2.4-1 libsoup2.4-1 libssl1.0.0 libstdc++6 libsystemd0 libtasn1-6 libtevent0 libtsan0 libubsan0 libudev1
libunity-protocol-private0 libunity-scopes-json-def-desktop libunity9 libupower-glib3 libusbmuxd4 libuuid1 libwbclient0 libwhoopsie0
libwnck-common libwnck22 libxml2 lightdm linux-firmware linux-generic linux-headers-generic linux-image-generic linux-libc-dev lsb-base
lsb-release lshw mount mtr-tiny mythes-en-us network-manager-gnome openssh-client openssl pidgin pidgin-data plymouth plymouth-label
plymouth-theme-ubuntu-text printer-driver-brlaser python2.7 python2.7-minimal python3-apport python3-commandnotfound python3-distupgrade
python3-problem-report python3-software-properties python3-uno python3-urllib3 python3.5 python3.5-minimal samba-libs sbsigntool
shared-mime-info snapd software-properties-common software-properties-gtk sudo systemd systemd-sysv thermald thunderbird
thunderbird-locale-en thunderbird-locale-en-us tzdata ubuntu-core-launcher ubuntu-drivers-common ubuntu-mono ubuntu-release-upgrader-core
ubuntu-release-upgrader-gtk udev uno-libs3 update-notifier update-notifier-common upower upstart ure util-linux uuid-runtime vim-common
vim-tiny wget whoopsie xbrlapi xinit xserver-common xserver-xorg-core
275 upgraded, 4 newly installed, 0 to remove and 1 not upgraded.
Need to get 447 MB/454 MB of archives.
After this operation, 329 MB of additional disk space will be used.
Do you want to continue? [Y/n]

若要「取消hold」，只要執行下面指令就行了。

$ sudo apt-mark unhold network-manager

註:

*「apt-mark」這個指令，在「這篇回覆」，我有提過，當時只是用來找尋被hold的套件。真的實際使用hold，也是在這次才使用，所以我不確定會不會有啥副作用。
* 以前相關的討論「16.04拒絕了dsl的使用者?」，「升級15.10後無法連線(已解決)」，我想樓主有參考過，只是附註在這，給未來有相關問題的人，可以找到相關參考。

## manpage

* man dpkg
* man dpkg-query
* man apt-mark
* man apt-cache
* man apt-get

更多套件操作實務，請參考這個「索引」。


## 相關參考

* Debian 參考手冊 / 2.2.10 套件狀態
* Debian 參考手冊 / 2.2.11 阻止套件升級

感謝 samwhelp 兄費心研究、指導，我會照著研作看看，再報告情況，謝謝您

備份連結

================================================


提供另一個操作步驟，設定「hold」。
概念上跟上面提到的是一樣的。

## 操作步驟

執行下面指令產生一個「list.txt」。

$ echo 'network-manager hold' > list.txt

執行下面指令，觀看「list.txt」的內容。

$ cat list.txt

顯示

network-manager hold

執行下面指令設定「hold」

$ sudo dpkg --set-selections < list.txt

上面執行完後，一樣可以使用上面回覆「使用的確認方法」。

這個方法，可以用在移除套件，我之前有紀錄在「這篇」，下方有個「select移除」。

samwhelp 兄:您好

我按7樓然後5樓的方式操作之後，
情形如附圖- 右上的NetworkManager圖示顯示已連線了，可是情況就如開文所說，
但 有個好處是
不用再每次開機都得重設一次pppoeconf

附件:

---

  Screenshot at 2016-07-25 16:50:50.png (36.82 KB)

Newman 寫到：
samwhelp 兄:您好

我按7樓然後5樓的方式操作之後，
情形如附圖- 右上的NetworkManager圖示顯示已連線了，可是情況就如開文所說，
但 有個好處是
不用再每次開機都得重設一次pppoeconf

不太懂您上面這一段話要表達的意思 :-p

所以先釐清一下

* 所以你目前同時使用「NetworkManager」和「pppoeconf」? (之前有討論到，這兩個不建議同時使用，還有要注意的事項)
* 若是單獨使用「NetworkManager」，你遇到的情形，還是跟你「一樓說的情形」一樣嗎？


若是跟「MRon」提到的，跟「DNS」有關，
我剛剛聯想到以前的「一篇討論」，
裡面提到的情形，跟你提到有點類似。

不過該篇的連線方式，應該不是使用「PPP連線」，
所以我推測你的情形，應該不是改「AP」的「DNS設定」。

若是朝「DNS」的方向，您就要研究，使用「NetworkManager」做「PPP連線」，DNS的設定方式。


## 相關參考資料

鳥哥的 Linux 私房菜 / 第十九章、主機名稱控制者： DNS 伺服器

關於這方面，我也沒有了解得很全面，我需要再學習，
我不確定你使用「NetworkManager」來做「PPP連線」，
是不是只要改「/etc/resolv.conf」就行了，
目前我尚未去探究實證，所以先提供你探究的方向。

或是有勞對這方面有概念的人來解惑了。

感恩先




=================================================


執行

$ cat /etc/resolv.conf

顯示

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 127.0.1.1

從「/etc/resolv.conf」第一行，可以找到相關的「manpage」。

* man 5 resolv.conf
* man 8 resolvconf

您好:
就是按序操作之後upgrade，
然後按adsl連線，顯示連線了，firefox 左上那個圈一直只是逆時針一直轉，進不到更上面我那附圖的畫面。
只好再設定sudo pppoeconf才又能連上線，而這時的「NetworkManager」顯示是「有線未受管理」。

在未按您的教序操作之前則是每次開機都得再設一次pppoeconf才能上網，現在則不必了，就醬~