CentOS 7.3 部署 IPsec L2TP 失败

其中安装 xl2tpd 的时候报错

[root@vps ~]# yum install -y xl2tpd
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: ftp.tsukuba.wide.ad.jp
 * epel: ftp.jaist.ac.jp
 * extras: ftp.tsukuba.wide.ad.jp
 * updates: ftp.tsukuba.wide.ad.jp
Resolving Dependencies
--> Running transaction check
---> Package xl2tpd.x86_64 0:1.3.8-1.el7 will be installed
--> Processing Dependency: kmod(l2tp_ppp.ko) for package: xl2tpd-1.3.8-1.el7.x86_64
--> Finished Dependency Resolution
Error: Package: xl2tpd-1.3.8-1.el7.x86_64 (epel)
           Requires: kmod(l2tp_ppp.ko)
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest
[root@vps ~]# 

请问该怎么解决呢