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How IPsec tunnel mode work without GRE
How is my GRE-Tunneled packet being routed?What problem does GRE solve?Pre-fragmentation for IPsec VPNs on cisco routersIn IPsec VPN, how is the pre-shared key encrypted?Two GRE tunnels in one subnetHow would “looping” in GRE occur according to RFC 2784GRE over IPsec between Juniper SRX100 and Fortigate 100DMPLS over GRE tunnel with Linux iproute2IPsec Tunnel is showing decrypt packets counter but 0 encryption packets: #pkts encaps: 0, #pkts encrypt: 0, #pkts digest: 0Layer 3 tunnel with Dynamic IP address
IPsec tunnel mode encrypt a whole IP packet and sent it as the payload of another IP packet. I have always used GRE as the encapsulation layer when doing IPsec encryption. However, how could I have the same behavior with a router that supports IPsec but does not implements GRE ?
ipsec tunnel gre
edited 7 hours ago
Cown
6,26131030
asked 8 hours ago
NakruleNakrule
15415
add a comment |
IPsec tunnel mode encrypt a whole IP packet and sent it as the payload of another IP packet. I have always used GRE as the encapsulation layer when doing IPsec encryption. However, how could I have the same behavior with a router that supports IPsec but does not implements GRE ?
ipsec tunnel gre
edited 7 hours ago
Cown
6,26131030
asked 8 hours ago
NakruleNakrule
15415
1
You've answered your own question in your first sentence: IPsec tunnel mode encrypts a whole IP packet and sends it as the payload of another IP packet. What part are you confused about?
– Ron Trunk
7 hours ago
So what's the difference between GRE+IPsec and IPsec only ?
– Nakrule
7 hours ago
You have a GRE tunnel protected by IPSec. If you drop the GRE tunnel part, IPSec is usually carried as a UDP stream.
– Ricky Beam
4 hours ago
add a comment |
IPsec tunnel mode encrypt a whole IP packet and sent it as the payload of another IP packet. I have always used GRE as the encapsulation layer when doing IPsec encryption. However, how could I have the same behavior with a router that supports IPsec but does not implements GRE ?
ipsec tunnel gre
edited 7 hours ago
Cown
6,26131030
asked 8 hours ago
NakruleNakrule
15415
IPsec tunnel mode encrypt a whole IP packet and sent it as the payload of another IP packet. I have always used GRE as the encapsulation layer when doing IPsec encryption. However, how could I have the same behavior with a router that supports IPsec but does not implements GRE ?
ipsec tunnel gre
ipsec tunnel gre
edited 7 hours ago
Cown
6,26131030
asked 8 hours ago
NakruleNakrule
15415
edited 7 hours ago
Cown
6,26131030
asked 8 hours ago
NakruleNakrule
15415
edited 7 hours ago
Cown
6,26131030
edited 7 hours ago
Cown
6,26131030
edited 7 hours ago
Cown
6,26131030
6,26131030
asked 8 hours ago
NakruleNakrule
15415
asked 8 hours ago
NakruleNakrule
15415
asked 8 hours ago
NakruleNakrule
15415
15415
1
You've answered your own question in your first sentence: IPsec tunnel mode encrypts a whole IP packet and sends it as the payload of another IP packet. What part are you confused about?
– Ron Trunk
7 hours ago
So what's the difference between GRE+IPsec and IPsec only ?
– Nakrule
7 hours ago
You have a GRE tunnel protected by IPSec. If you drop the GRE tunnel part, IPSec is usually carried as a UDP stream.
– Ricky Beam
4 hours ago
add a comment |
1
You've answered your own question in your first sentence: IPsec tunnel mode encrypts a whole IP packet and sends it as the payload of another IP packet. What part are you confused about?
– Ron Trunk
7 hours ago
So what's the difference between GRE+IPsec and IPsec only ?
– Nakrule
7 hours ago
You have a GRE tunnel protected by IPSec. If you drop the GRE tunnel part, IPSec is usually carried as a UDP stream.
– Ricky Beam
4 hours ago
1
1
You've answered your own question in your first sentence: IPsec tunnel mode encrypts a whole IP packet and sends it as the payload of another IP packet. What part are you confused about?
– Ron Trunk
7 hours ago
You've answered your own question in your first sentence: IPsec tunnel mode encrypts a whole IP packet and sends it as the payload of another IP packet. What part are you confused about?
– Ron Trunk
7 hours ago
So what's the difference between GRE+IPsec and IPsec only ?
– Nakrule
7 hours ago
So what's the difference between GRE+IPsec and IPsec only ?
– Nakrule
7 hours ago
You have a GRE tunnel protected by IPSec. If you drop the GRE tunnel part, IPSec is usually carried as a UDP stream.
– Ricky Beam
4 hours ago
You have a GRE tunnel protected by IPSec. If you drop the GRE tunnel part, IPSec is usually carried as a UDP stream.
– Ricky Beam
4 hours ago
add a comment |
1 Answer
1
active
oldest
votes
So what's the difference between GRE+IPsec and IPsec only?
In GRE+IPsec the original IP packet is encapsulated in a GRE tunnel packet. The GRE packet is then encapsulated in the IPSec packet.
The most common reason for doing this is to allow broadcast and multicast across the tunnel. Neither is supported by IPSec alone. GRE can also encapsulate non-IP traffic, which IPsec does not support.
answered 7 hours ago
Ron TrunkRon Trunk
37k33475
tunnel mode ipsec ipv4(or the preferred vendor's equivalent of "tunnel based vpn" or "interface based vpn") will nicely support multicast routing across the tunnel and will allow the multicast based IGPs to form their adjacencies and neighborships, without the need for GRE. Non-IP protocols of course won't work, which they might with GRE.
– Marc 'netztier' Luethi
4 hours ago
add a comment |
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1 Answer
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1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
So what's the difference between GRE+IPsec and IPsec only?
In GRE+IPsec the original IP packet is encapsulated in a GRE tunnel packet. The GRE packet is then encapsulated in the IPSec packet.
The most common reason for doing this is to allow broadcast and multicast across the tunnel. Neither is supported by IPSec alone. GRE can also encapsulate non-IP traffic, which IPsec does not support.
answered 7 hours ago
Ron TrunkRon Trunk
37k33475
tunnel mode ipsec ipv4(or the preferred vendor's equivalent of "tunnel based vpn" or "interface based vpn") will nicely support multicast routing across the tunnel and will allow the multicast based IGPs to form their adjacencies and neighborships, without the need for GRE. Non-IP protocols of course won't work, which they might with GRE.
– Marc 'netztier' Luethi
4 hours ago
add a comment |
So what's the difference between GRE+IPsec and IPsec only?
In GRE+IPsec the original IP packet is encapsulated in a GRE tunnel packet. The GRE packet is then encapsulated in the IPSec packet.
The most common reason for doing this is to allow broadcast and multicast across the tunnel. Neither is supported by IPSec alone. GRE can also encapsulate non-IP traffic, which IPsec does not support.
answered 7 hours ago
Ron TrunkRon Trunk
37k33475
tunnel mode ipsec ipv4(or the preferred vendor's equivalent of "tunnel based vpn" or "interface based vpn") will nicely support multicast routing across the tunnel and will allow the multicast based IGPs to form their adjacencies and neighborships, without the need for GRE. Non-IP protocols of course won't work, which they might with GRE.
– Marc 'netztier' Luethi
4 hours ago
add a comment |
So what's the difference between GRE+IPsec and IPsec only?
In GRE+IPsec the original IP packet is encapsulated in a GRE tunnel packet. The GRE packet is then encapsulated in the IPSec packet.
The most common reason for doing this is to allow broadcast and multicast across the tunnel. Neither is supported by IPSec alone. GRE can also encapsulate non-IP traffic, which IPsec does not support.
answered 7 hours ago
Ron TrunkRon Trunk
37k33475
So what's the difference between GRE+IPsec and IPsec only?
In GRE+IPsec the original IP packet is encapsulated in a GRE tunnel packet. The GRE packet is then encapsulated in the IPSec packet.
The most common reason for doing this is to allow broadcast and multicast across the tunnel. Neither is supported by IPSec alone. GRE can also encapsulate non-IP traffic, which IPsec does not support.
answered 7 hours ago
Ron TrunkRon Trunk
37k33475
answered 7 hours ago
Ron TrunkRon Trunk
37k33475
answered 7 hours ago
Ron TrunkRon Trunk
37k33475
answered 7 hours ago
Ron TrunkRon Trunk
37k33475
37k33475
tunnel mode ipsec ipv4(or the preferred vendor's equivalent of "tunnel based vpn" or "interface based vpn") will nicely support multicast routing across the tunnel and will allow the multicast based IGPs to form their adjacencies and neighborships, without the need for GRE. Non-IP protocols of course won't work, which they might with GRE.
– Marc 'netztier' Luethi
4 hours ago
add a comment |
tunnel mode ipsec ipv4(or the preferred vendor's equivalent of "tunnel based vpn" or "interface based vpn") will nicely support multicast routing across the tunnel and will allow the multicast based IGPs to form their adjacencies and neighborships, without the need for GRE. Non-IP protocols of course won't work, which they might with GRE.
– Marc 'netztier' Luethi
4 hours ago
tunnel mode ipsec ipv4 (or the preferred vendor's equivalent of "tunnel based vpn" or "interface based vpn") will nicely support multicast routing across the tunnel and will allow the multicast based IGPs to form their adjacencies and neighborships, without the need for GRE. Non-IP protocols of course won't work, which they might with GRE.– Marc 'netztier' Luethi
4 hours ago
tunnel mode ipsec ipv4 (or the preferred vendor's equivalent of "tunnel based vpn" or "interface based vpn") will nicely support multicast routing across the tunnel and will allow the multicast based IGPs to form their adjacencies and neighborships, without the need for GRE. Non-IP protocols of course won't work, which they might with GRE.– Marc 'netztier' Luethi
4 hours ago
add a comment |
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1
You've answered your own question in your first sentence: IPsec tunnel mode encrypts a whole IP packet and sends it as the payload of another IP packet. What part are you confused about?
– Ron Trunk
7 hours ago
So what's the difference between GRE+IPsec and IPsec only ?
– Nakrule
7 hours ago
You have a GRE tunnel protected by IPSec. If you drop the GRE tunnel part, IPSec is usually carried as a UDP stream.
– Ricky Beam
4 hours ago