Rodney Callahan appeals from his guilty-plea conviction and 240-month sentence imposed for distribution of cocaine base, in violation of 21 U.S.C. § 841(a)(1), (b)(l)(A)(iii) and being a felon in possession of a firearm, in violation of 18 U.S.C. § 922(g)(1).

Pursuant to Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967), Callahan’s counsel has filed a brief stating there are no grounds for relief, along with a motion to withdraw as counsel of record. No pro se supplemental brief has been filed.

Our independent review of the record pursuant to Penson v. Ohio, 488 U.S. 75, 82-83, 109 S.Ct. 346, 102 L.Ed.2d 300 (1988), indicates that Callahan knowingly and voluntarily waived the right to appeal his sentence and was sentenced within the terms of the plea agreement. We therefore enforce the waiver and dismiss the appeal as to his sentence. See United States v. Nguyen, 235 F.3d 1179, 1182 (9th Cir. 2000) (stating that an appeal waiver is valid when it is entered knowingly and voluntarily).

With regard to his conviction and the conditions of supervised release from which Callahan retained his right to appeal, our independent review of the record discloses no grounds for relief, and we affirm.

Counsel’s motion to withdraw is GRANTED, and the appeal is DIS*576MISSED in part and AFFIRMED in part.