GREVPN配置！！！！
说明：R2相当i
ter
et，在R1和R3之间建立隧道，R1，R3的环回端口模拟私网。配置GREVPN只能配置静态路由，因为GRE不支持组播
lo0：1921681001
S10：12111
S1012112
S1123113
R1
R2
S1123112
R3
lo01921682001
R1
e
co
fthostr1i
ts10ipadd121112552552550
oshuti
tlo0ipadd19216810012552552550exitiproute0000000012112i
ttu
el0ipadd1001112552552550tu
elsources10tu
eldesti
atio
23113
oshutexitiproute19216820002552552550tu
el0exitR2e
co
fthostr2i
ts10ipadd121122552552550
oshuti
ts11ipadd231122552552550
oshutexit
fR3e
co
fthostr3i
ts11ipadd231132552552550
oshuti
tlo0ipadd19216820012552552550exitiproute0000000023112i
ttu
el0ipadd1001122552552550tu
elsources11tu
eldesti
atio
12111
oshutexitiproute19216810002552552550tu
el0exit
fr