All following observations about IPSec are correct except:

HMAC-MD5 and HMAC-SHA-1 are indeed commonly used and default hashing algorithms for IPSec for data integrity and authentication.

DES (in CBC mode) was a common default or supported encryption algorithm for IPSec, although more robust algorithms like AES are now preferred and widely supported. The 'but other' implies flexibility.

IPSec explicitly supports two primary communication modes: Transport mode (for end-to-end host communication) and Tunnel mode (for network-to-network or host-to-network communication via gateways).

This statement is NOT correct. While IPSec uses symmetric (secret key) cryptography for bulk data encryption (e.g., DES, 3DES, AES), it uses asymmetric (public key) cryptography during the Internet Key Exchange (IKE) phase for establishing secure channels, authenticating peers, and negotiating shared secret keys. Therefore, IPSec does not work only with secret Key Cryptography.