[strongSwan] why multiple SAs for one peer?

[Victor Sudakov]

Dear Colleagues,

What's the reason for strongSwan to create (sometimes) multiple SAs for
a single peer? Please see the example below where the "officeru3" peer
looks fine to me while the "officeru4" peer has an extraneous SA.

root at tunn:~# ipsec status | grep officeru3
   officeru3{2}:  ROUTED, TRANSPORT, reqid 2
   officeru3{2}:   x.x.x.x/32[gre] === y.y.y.y/32[gre]
   officeru3[27]: ESTABLISHED 108 minutes ago, x.x.x.x[x.x.x.x]...y.y.y.y[y.y.y.y]
   officeru3{83}:  INSTALLED, TRANSPORT, reqid 2, ESP in UDP SPIs: c1f542b3_i 0e4df460_o
   officeru3{83}:   x.x.x.x/32[gre] === y.y.y.y/32[gre]
root at tunn:~# 
root at tunn:~# ipsec status | grep officeru4
   officeru4{3}:  ROUTED, TRANSPORT, reqid 3
   officeru4{3}:   x.x.x.x/32[gre] === z.z.z.z/32[gre]
   officeru4[30]: ESTABLISHED 60 minutes ago, x.x.x.x[x.x.x.x]...z.z.z.z[z.z.z.z]
   officeru4{82}:  INSTALLED, TRANSPORT, reqid 3, ESP in UDP SPIs: c50d4bb3_i 0f33c281_o
   officeru4{82}:   x.x.x.x/32[gre] === z.z.z.z/32[gre]
   officeru4[28]: ESTABLISHED 106 minutes ago, x.x.x.x[x.x.x.x]...z.z.z.z[z.z.z.z]
   officeru4{84}:  INSTALLED, TRANSPORT, reqid 3, ESP in UDP SPIs: c02ebd2f_i 0a5e786d_o
   officeru4{84}:   x.x.x.x/32[gre] === z.z.z.z/32[gre]
root at tunn:~# 

-- 
Victor Sudakov,  VAS4-RIPE, VAS47-RIPN
2:5005/49 at fidonet http://vas.tomsk.ru/