本来是可以上网的，是用 pppoeconf 设置的，但最近不能上网了，重新pppoeconf也不行
$ plog
Dec 23 16:21:18 localhost pppd[9081]: pppd 2.4.3 started by clk, uid 1000
Dec 23 16:21:18 localhost pppd[9081]: PPP session is 118
Dec 23 16:21:18 localhost pppd[9081]: Using interface ppp0
Dec 23 16:21:18 localhost pppd[9081]: Connect: ppp0 <--> eth0
Dec 23 16:21:18 localhost pppd[9081]: Couldn't increase MTU to 1500
Dec 23 16:21:18 localhost pppd[9081]: Couldn't increase MRU to 1500
Dec 23 16:21:21 localhost pppd[9081]: Couldn't increase MRU to 1500
Dec 23 16:21:21 localhost pppd[9081]: CHAP authentication failed: Passwd_Err
Dec 23 16:21:21 localhost pppd[9081]: Couldn't increase MTU to 1500
Dec 23 16:21:21 localhost pppd[9081]: Couldn't increase MRU to 1500
不知道如何解决，求助 。 （帐户和密码应该没有错的）
