In which two modes do IPv6-in-IPv4 tunnels operate? (Choose two.)
A.
tunnel mode
B.
transport mode
C.
6to4 mode
D.
4to6 mode
E.
ISATAP mode
which two modes do IPv6-in-IPv4 tunnels operate?
In which two modes do IPv6-in-IPv4 tunnels operate? (Choose two.)
i think that the answer is C, E
Explanation: *There are 5 tunneling solution in IPv6:*
*1. Using the “Tunnel mode ipv6ip”, in this case the tunnel source anddestination are configured
with IPv4 addressing and the tunnel interface isconfigured with IPv6. This will use protocol 41.
This is used for IPv6/IPv4.*
R1(config)#int tunnel 1
R1(config-if)#ipv6 address 12:1:12::1/64
R1(config-if)#tunnel source 10.1.12.1
R1(config-if)#tunnel destination 10.1.12.2
R1(config-if)#*tunnel mode ipv6ip*
*2. Using the “Tunnel mode gre ipv6, in this case the tunnel source anddestination are all
configured with IPv6 addressing. This is used forIPv6/IPv6. *
BB1(config)#int tunnel 1
BB1(config-if)#ipv6 address 121:1:121::111/64
BB1(config-if)#tunnel source 10:1:111::111
BB1(config-if)#tunnel destination 10:1:112::112
BB1(config-if)#*tunnel mode gre ipv6*
*3. In this case, the third type, the tunnel mode is NOT used at all, notethat the tunnel interface is
configured with IPv6 and the tunnel source anddestination is configured with IPv4 but no mention
of tunnel mode. Thisconfiguration will use protocol 47. This is used for IPv6/IPv4. *
R1(config)#int tunnel 13
R1(config-if)#ipv6 address 13:1:13::1/64
R1(config-if)#tunnel source 10.1.13.1
R1(config-if)#tunnel destination 10.1.13.3
*4. Note in this case a special addressing is assigned to the tunnelinterface which is a
concatenation of a reserved IPv6 address of2002followed by the translatedIPv4 address of a given
interface on the router. In this configuration ONLYthe tunnel source address is used and since the
tunnel is automatic,the destinationaddress is NOT configured. The tunnel mode is set to “Tunnel
mode ipv6ip6to4. Note the IPv4 address of 10.1.1.1 is translated to 0A.01.01.01 andonce
concatenated, it will be “2002:0A01:0101: or 2002:A01:101. This is usedfor IPv6/IPv4.*
R1(config)#interface Tunnel14
R1(config-if)#ipv6 address 2002:A01:101::/128
R1(config-if)#tunnel source 10.1.1.1
R1(config-if)#*tunnel mode ipv6ip 6to4*
*5. ISATAP, ISATAP works like 6to4 tunnels, with one major difference, ituses a special IPv6 address which is formed as follows: *
*In this tunnel mode, the network portion can be any IPv6 address, whereasin 6to4 it had to start
with 2002.*
*Note when the IPv6 address is assigned to the tunnel interface, the“eui-64 is used, in this case
the host portion of the IPv6 address startswith “0000.5EFE” and then the rest of the host portion is
the translatedIPv4 address of the tunnel’s source IPv4 address. This translation isperformed
automatically unlike 6to4. This is used for IPv6/IPv4.*
R4(config)#int tunnel 46
R4(config-if)#ipv6 address 46:1:46::/64 eui-64
R4(config-if)#tunnel source 10.44.44.44
R4(config-if)#*tunnel mode ipv6ip ISATAP*
Correct: C & E
They might be talking about RFC4891, using IPSEC to secure IPv6-in-IPv4 tunnels. That mentions tunnel mode and transport mode. I say that because of the way they worded the question. It implies that ALL the IPv6-in-IPv4 tunnels operate in two modes, which for IPSEC would be tunnel and transport … but of course they don’t specifically mention IPSEC. So depending on how you interpret what they are asking for it could be C & E or A & B.