09-13-2017 02:36 PM - edited 03-08-2019 12:01 PM
Trying to get cts manual to work between two switches with GCM-AES-256
How do I even change from GCM-AES-128 to GCM-AES-256 ?
listed below as "supported", can't find any usefull information about this topic
WS-C3650-24TS 16.3.3 ipbasek9
interface GigabitEthernet1/1/2 description Trunk switchport trunk native vlan 3 switchport mode trunk switchport nonegotiate cts manual no propagate sgt sap pmk 01234 mode-list gcm-encrypt Switch#sh macsec int g1/1/2 MACsec is enabled Replay protect : enabled Replay window : 0 Include SCI : yes Use ES Enable : no Use SCB Enable : no Admin Pt2Pt MAC : forceTrue(1) Pt2Pt MAC Operational : no Cipher : GCM-AES-128 Confidentiality Offset : 0 Capabilities ICV length : 16 Data length change supported: yes Max. Rx SA : 16 Max. Tx SA : 16 Max. Rx SC : 8 Max. Tx SC : 8 Validate Frames : strict PN threshold notification support : Yes Ciphers supported : GCM-AES-128 GCM-AES-256 Transmit Secure Channels SCI : 58AC78D7EE1A0000 SC state : notInUse(2) Elapsed time : 00:06:55 Start time : 7w0d Current AN: 0 Previous AN: - Next PN: 0 SA State: notInUse(2) Confidentiality : no SAK Unchanged : no SA Create time : 00:30:44 SA Start time : 7w0d SC Statistics Auth-only Pkts : 0 Auth-only Bytes : 0 Encrypt Pkts : 0 Encrypt Bytes : 0 SA Statistics Auth-only Pkts : 0 Encrypt Pkts : 1092 Port Statistics Egress untag pkts 0 Egress long pkts 1098379227928 Receive Secure Channels SCI : 74A02F8FA2810000 SC state : notInUse(2) Elapsed time : 00:06:58 Start time : 7w0d Current AN: 0 Previous AN: - Next PN: 0 RX SA Count: 0 SA State: notInUse(2) SAK Unchanged : no SA Create time : 00:30:44 SA Start time : 7w0d SC Statistics Notvalid pkts 0 Invalid pkts 0 Valid pkts 0 Valid bytes 0 Late pkts 0 Uncheck pkts 0 Delay pkts 0 UnusedSA pkts 0 NousingSA pkts 0 Decrypt bytes 0 SA Statistics Notvalid pkts 0 Invalid pkts 0 Valid pkts 148 UnusedSA pkts 0 NousingSA pkts 0 Port Statistics Ingress untag pkts 1099150680408 Ingress notag pkts 21 Ingress badtag pkts 0 Ingress unknownSCI pkts 0 Ingress noSCI pkts 0 Ingress overrun pkts 1098492218128
Switch#sh cts int g1/1/2
Global Dot1x feature is Disabled
Interface GigabitEthernet1/1/2:
CTS is enabled, mode: MANUAL
IFC state: OPEN
Interface Active for 00:16:10.232
Authentication Status: NOT APPLICABLE
Peer identity: "unknown"
Peer's advertised capabilities: "sap"
Authorization Status: NOT APPLICABLE
SAP Status: SUCCEEDED
Version: 2
Configured pairwise ciphers:
gcm-encrypt
Replay protection: enabled
Replay protection mode: STRICT
Selected cipher: gcm-encrypt
Propagate SGT: Disabled
Cache Info:
Expiration : N/A
Cache applied to link : NONE
Statistics:
authc success: 0
authc reject: 0
authc failure: 0
authc no response: 0
authc logoff: 0
sap success: 3
sap fail: 0
authz success: 0
authz fail: 0
port auth fail: 0
L3 IPM: disabled.
CTS sgt-caching Ingress : Disabled
CTS sgt-caching Egress : Disabled
01-15-2018 09:08 AM
Did anyone find an a solution?
01-15-2018 02:51 PM
08-17-2018 12:15 AM
Hello guys,
I use IOS 16.9.1.
How can I activate gcm-aes-256 ?
08-22-2018 01:35 PM - edited 08-22-2018 01:43 PM
Example:
! key chain MS-KC macsec key 01 cryptographic-algorithm aes-256-cmac key-string ABCDABCDABCDABCDABCDABCDABCDABCDABCDABCDABCDABCDABCDABCDABCDABCD ! mka policy your-pol delay-protection macsec-cipher-suite gcm-aes-256 confidentiality-offset 30 ! interface X/X/X macsec network-link mka policy your-pol mka pre-shared-key key-chain MS-KC !
Beware of this:
Prior to Cisco IOS XE Fuji 16.8.1a, should-secure was supported for MKA and SAP. With should-secure enabled, if the peer is configured for MACsec, the data traffic is encrypted, otherwise it is sent in clear text. Starting with Cisco IOS XE Fuji 16.8.1a, must-secure support is enabled on both the ingress and the egress. Must-secure is supported for MKA and SAP. With must-secure enabled, only EAPoL traffic will not be encrypted. The rest of the traffic will be encrypted. Unencrypted packets are dropped.
09-18-2018 11:05 PM
11-14-2018 03:29 AM
Hi Szabolcs,
I also tested your solution with IOS XE 16.6.4 and it seems to work fine.
Thanks, Benjamin
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